Some people try to knock me down, only     me more determined to do better．

         A．to make     B．makes        C．having made      D．made

Some plants get so hungry they eat flies, spiders, and even small frogs. What’s more amazing is that these plants occur naturally (in special environment) in every state. In fact, they’re found on every continent except Antarctica.

You’ve probably seen a Venus’ flytrap. It’s often sold in museum gift stores, department stores, and even supermarkets. A small plant, it grows 6 to 8 inches tall in a container. At the end of its stalks（茎）are specially modified leaves that act like traps. Inside each trap is a lining of tiny trigger(触发) hairs. When an insect lands on them, the trap suddenly shut. Over the course of a week or so, the plant feeds on its catch.

The Venus’ flytrap is just one of more than 500 species of meat-eating plants, says Barry Meyers-Rice, the editor of the International Carnivorous Plant Society’s Newsletter. Note: Despite any science –fiction stories you might have read, no meat-eating plant does any danger to humans.

Dr. Meyers-Rice says a plant is meat-eating, only if it does all four of the following: “attract, kill, digest, and absorb” some forms of insects, including flies, butterflies, and moths. Meat-eating plants look and act like other green plants ---well, most of the time.

All green plants make sugar through a process called photosynthesis(光合作用). Plants use the sugar to make food. What makes “meat-eating” plants different is their bug-catching leaves. They need insects for one reason: nitrogen(氮). Nitrogen is a nutrient that they can’t obtain any other way. Why almost all green plants on our planet get nitrogen from the soil “Meat-eating” plants can’t. They live in places where nutrients are hard or almost impossible to get from the soil because of its acidity(酸度). So they’ve come to rely on getting nitrogen from insects and small animals. In fact, nutrient-rich soil is poisonous to “meat-eating” plants. Never fertilize(施肥)them! But don’t worry, either, if they never seem to catch any insects. They can survive, but they’ll grow very slowly.

1.According to the passage, carnivorous plants       .

2.Venus’ flytrap preys on insects by          .

3.We can conclude from the third paragraph that_____.

4.In the eyes of the author, which of the following statements is TRUE?

Hundreds of years ago, life was much harder than it is today, people did not have modern machines. There was no modern medicine, either.
Life today has brought new problems. One of the biggest is pollution. Water pollution has made our rivers and lakes dirty. It kills our fish and affects our drinking water. Noise pollution makes us talk louder and become angry more easily. Air pollution is the most serious kind of pollution. It affects every living thing in the world.
Cars, planes and factories all pollute our air every day. Sometimes the pollution is so thick that it is like a quilt(被子) over a city. This kind of quilt is called smog.
Many countries are making new laws to fight pollution. Factories must now clean their water before it is thrown away; they mustn’t blow dirty smoke into the air.
We need to do many other things. We can put waste things in the dustbin and not throw them on the ground. We can go to work by bus or with our friends in the some car. If there are fewer people driving, there will be less pollution.
Laws are not enough. Every person must help to fight pollution.
49. Life was harder hundreds of years ago because____________.
A. the weather was bad             B. there were no cities
C. people had no modern machines    D. people couldn’t make machines  
50._______ makes the rivers and lakes dirty.
A Swimming.   B Polluted water   C. Growing population   D. Warmer weather
51.More and more people become angry easily because __________.
A. they can’t get enough money           B. They are often hungry
C. there’s much traffic on the roads        D. there’s much noise around them
52 The writer of the passage thinks__________.
A. everyone should do something to fight pollution
B. all the laws can stop factories going on polluting
C few countries can stop the air and water being polluting
D. people have to live in the polluted air..