73.From the passage we know that the evolutionary scale is graded according to . A.evolutionary cycles B.heights and depths C.time D.kinds 查看更多

 

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All plant cells are capable of taking up water. Even dead ones do to a certain degree. Absorption(吸收)of water by dead cell walls makes wood become larger. In common land plants, the living cells of roots take up most of the water. Land plants without roots do exist, however. Those greenish-yellow lichens(苔藓)you see on rocks in the high mountains have no roots. Half a billion years ago, when water plants started to enter the land, the first land plants did not have roots.

Even among the flowering plants, one finds rootless forms. These flowering plants are “the higher plants” because they evolved(进化)recently and are thus considered higher on the evolutionary scale(进化度). In the Peruvian desert, there grows one of these rootless higher plants, a bromeliad. It is a relative of the pineapple. Even if this plant had roots, they would be of no use, because where the plant grows, it never rains. The plant gets its water only from the dew(露水)it collects at night, when its leaves cool off. Such rootless plants, of course, can be moved with ease, but they will only grow when they are placed out in the open. If they are placed too near a house, the radiation from the heat of the house prevents the leaves from cooling and so prevents dew from forming, and the plant dies. In the southern United States and in Puerto Rico, one sees bromeliads growing high above the streets on the insulation(绝缘物)of electric wires. These plants get their water from rain, and the only soil they ever come in contact with is the dust that may blow on their leaves.

72.Wood becomes larger because of    .

A.dead cell walls                                    B.water entering dead cells

C.the growth of cells                               D.the death of cells

73.From the passage we know that the evolutionary scale is graded according to    .

A.evolutionary cycles         B.heights and depths  C.time  D.kinds

74.The “bromeliad” is a plant that   .

A.has useless roots                                  B.is a pineapple

C.can grow anywhere                       D.takes up water through its leaves

75.The most suitable title for this passage is “    ”.

A.Absorption of water by plants                   B.Rootless plants

C.Plants in the desert                                   D.Higher plants

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All plant cells are capable of taking up(吸收)water. Even dead ones do to a certain degree. Absorption(吸收)of water by dead cell walls makes wood become larger.
In common land plants, the living cells of roots take upmost of the water. Land plants without roots do exist, however. Those greenish-yellow lichens(苔藓)you see on rocks in the high mountains have no roots. Half a billion years ago, when water plants started to enter the land, the first land plants did not have roots.
Even among the flowering plants, one finds rootless forms. These flowering plants are “the higher plants” because they evolved(进化)recently and are thus considered higher on the evolutionary scale(进化度).
In the Peruvian desert, there grows one of these rootless higher plants, a bromeliad. It is a relative of the pineapple. Even if this plant had roots, they would be of no use, because where the plant grows, it never rains. The plant gets its water only from the dew(露水)it collects at night, when its leaves cool off. Such rootless plants, of course, can be moved with ease, but they will only grow when they are placed out in the open. If they are placed too near a house, the radiation from the heat of the house prevents the leaves from cooling and so prevents dew from forming, and the plant dies.
In the southern United States and in Puerto Rico, one sees bromeliads growing high above the streets on the insulation(绝缘物)of electric wires. These plants get their water from rain, and the only soil they ever come in contact with is the dust that may blow on their leaves.
【小题1】Wood becomes larger because of       .

A.dead cell wallsB.water entering dead cells
C.the growth of cellsD.the death of cells
【小题2】From the passage we know that the evolutionary scale is graded according to      .
A.evolutionary cyclesB.heights and depths
C.timeD.kinds
【小题3】The “bromeliad” is a plant that     .
A.has no rootsB.is a pineapple
C.can grow anywhereD.takes up water through its leaves
【小题4】The most suitable title for this passage is “      ”.
A.Absorption of water by plantsB.Rootless plants in America
C.Plants in the desertD.Higher plants

查看答案和解析>>

All plant cells are capable of taking up(吸收)water. Even dead ones do to a certain degree. Absorption(吸收)of water by dead cell walls makes wood become larger.

In common land plants, the living cells of roots take upmost of the water. Land plants without roots do exist, however. Those greenish-yellow lichens(苔藓)you see on rocks in the high mountains have no roots. Half a billion years ago, when water plants started to enter the land, the first land plants did not have roots.

         Even among the flowering plants, one finds rootless forms. These flowering plants are “the higher plants” because they evolved(进化)recently and are thus considered higher on the evolutionary scale(进化度).

In the Peruvian desert, there grows one of these rootless higher plants, a bromeliad. It is a relative of the pineapple. Even if this plant had roots, they would be of no use, because where the plant grows, it never rains. The plant gets its water only from the dew(露水)it collects at night, when its leaves cool off. Such rootless plants, of course, can be moved with ease, but they will only grow when they are placed out in the open. If they are placed too near a house, the radiation from the heat of the house prevents the leaves from cooling and so prevents dew from forming, and the plant dies.

In the southern United States and in Puerto Rico, one sees bromeliads growing high above the streets on the insulation(绝缘物)of electric wires. These plants get their water from rain, and the only soil they ever come in contact with is the dust that may blow on their leaves.

1.Wood becomes larger because of       .

A.dead cell walls                                                 B.water entering dead cells

C.the growth of cells                                          D.the death of cells

2.From the passage we know that the evolutionary scale is graded according to       .

A.evolutionary cycles                                         B.heights and depths

C.time                                                                    D.kinds

3.The “bromeliad” is a plant that      .

A.has no roots                                            B.is a pineapple

C.can grow anywhere                         D.takes up water through its leaves

4.The most suitable title for this passage is “       ”.

A.Absorption of water by plants            B.Rootless plants in America

C.Plants in the desert                         D.Higher plants

 

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  All plant cells are capable of taking up water.Even dead ones do to a certain degree.Absorption of water by dead cell walls makes wood become larger.In common land plants, the living cells of roots take up most of the water.Land plants without roots do exist, however.Those greenish-yellow lichens (苔藓) you see on rocks in the high mountains have no roots.Half a billion years ago, when water plants started to enter the land, the first land plants did not have roots.

  Even among the flowering plants, one finds rootless forms.These flowering plants are the higher plants because they evolved (进化) recently and are thus considered higher on the evolutionary scale (进化树).In the Peruvian desert, there grows one of these rootless higher plants, a bromeliad.It is a relative of the pineapple.Even if this plant had roots, they would be of no use, because where the plant grows, it never rains.The plant gets its water only from the dew (露水) it collects at night, when its leaves cool off.Such rootless plants, of course, can be moved with ease, but they will only grow when they are placed out in the open.If they are placed too near a house, the radiation from the heat of the house prevents the leaves from cooling and so prevents dew from forming, and the plant dies.In the southern United States and in Puerto Rico, one sees bromeliads growing high above the streets on the insulation (绝缘物) of electric wires.These plants get their water from rain, and the only soil they ever come in contact with is the dust that may blow on their leaves.

1.Wood becomes larger because of________.

[  ]

A.plants having roots

B.water entering dead cell walls

C.the growth of cells

D.the death of cells

2.From the passage we know that the evolutionary scale is graded according to ________.

[  ]

A.evolutionary cycles
B.heights and depths
C.time evolution takes
D.species of plant

3.The bromeliad is a plant that________.

[  ]

A.has useless roots

B.resembles a pineapple

C.can grow anywhere

D.takes up water through its leaves

4.The most suitable title for this passage is________.

[  ]

A.Absorption of Water by Plants

B.Rootless Plants

C.Plants in the Desert

D.Higher Plants

查看答案和解析>>

All plant cells are capable of taking up water. Even dead ones do to a certain degree. Absorption(吸收)of water by dead cell walls makes wood become larger. In common land plants, the living cells of roots take up most of the water. Land plants without roots do exist, however. Those greenish-yellow lichens(苔藓)you see on rocks in the high mountains have no roots. Half a billion years ago, when water plants started to enter the land, the first land plants did not have roots.

Even among the flowering plants, one finds rootless forms. These flowering plants are “the higher plants” because they evolved(进化)recently and are thus considered higher on the evolutionary scale(进化度). In the Peruvian desert, there grows one of these rootless higher plants, a bromeliad. It is a relative of the pineapple. Even if this plant had roots, they would be of no use, because where the plant grows, it never rains. The plant gets its water only from the dew(露水)it collects at night, when its leaves cool off. Such rootless plants, of course, can be moved with ease, but they will only grow when they are placed out in the open. If they are placed too near a house, the radiation from the heat of the house prevents the leaves from cooling and so prevents dew from forming, and the plant dies. In the southern United States and in Puerto Rico, one sees bromeliads growing high above the streets on the insulation(绝缘物)of electric wires. These plants get their water from rain, and the only soil they ever come in contact with is the dust that may blow on their leaves.

64.From the passage we know that the evolutionary scale is graded according to _______ .

       A. evolutionary cycles  B. heights and depths

       C. time         D. kinds

65.The “bromeliad” is a plant that _______ .

       A.has useless roots             B. is a pineapple

       C.can grow anywhere  D. takes up water through its leaves

66.The most suitable title for this passage is “_______ ”.

       A. Absorption of water by plants   B. Rootless plants

       C. Plants in the desert        D. Higher plants

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