Plants don’t have legs to run or arms to throw a ball, but that doesn’t  21  that plants can’t 22at all． If you watch closely, you will see 23 plants bend their stems and flowers toward the sunlight every day． 24  are plants able to move   25 they don’t have bodies like animals do?

       Plants cells  26  chemicals called auxins（植物生长素） to   27  them to move． To find out how chemicals   28,  think of a plant outside in a garden． Because the sun  rise in the east in the morning, the   29 side of the plant stem is in the light． But the west side of the stem is in the _30 ． So the cells in the shaded side of the stem   31 to make auxins, which make that side of the stem grow  32  while the side of the stem   33  the sun grows much slower．  When the shaded side grows faster, it makes the whole stem  34  toward the sunlight, and  35  leaves and flowers on the stem face the 36  too． When the sun moves to the west in the afternoon, the   37  thing happens and the stem bends toward the light again．

       38   is a reason why the plant produces chemicals that make stems 39  the sun．  Leaves  40 sunlight to make food for the plant． So it is important for stem to get as much light as they can．

21．A． tell                   B． promise           C． show               D． mean

22．A． grow                B． go               C． move               D． stand

23．A． most                 B． few              C． tall                 D． short

24．A． why                 B． How              C． Where              D． When

25．A． because              B． although           C． if                  D． as soon as

26．A． make                B． accept            C． keep               D． send

27．A． push                B． bring             C． help                D． stop

28．A． form                B． work             C． flow               D． look at

29．A． west                B． bright            C． opposite            D east

30．A． shade                B． light              C． dark               D． garden

31．A． stop                 B． begin           C． continue             D． help

32．A． fast                 B． slowly            C． up                 D． badly

33．A． near                 B． toward           C． against             D． in

34．A． bend                B． fall               C． turn                D． walk

35．A． some              B． all                 C． few                D． no

36．A． stem               B． west              C． ground             D． sun

37．A． common           B． strange            C． same               D． different

38．A． This                B． That             C． It                 D． There

39．A． follow             B． circle             C． catch              D． pull

40．A． receive             B． have             C． use                D． reduce

Many animals use some kinds of “language”. They use signals(信号) and the signals have meanings. For example, 1 a bee has found some food, it goes 　2 its home. 　3　 is difficult for a bee to tell 4 bees where the food is speaking to them, but it can do a little dancing. This tells the bees where the food is and 　5 it is.

Some animals show 　6 they feel by making sounds. It is not difficult to tell if a dog is angry because it barks. Birds make several different sounds and 　7 has its meaning. Sometimes we humans make sounds in the same way. We make sounds like “Oh” to 　8 how we feel about 9 or we 　10 something on our feet.

We humans have languages. We have words. These words have meaning of things, action, feeling or ideas. We are able to 11 each other information, to tell other people 12 we think or we feel. By writing down words, we can remember what has happened or 13 messages to people far away.

Languages, like people, live and die. If a language is not used by people, it is called a dead language. This language cannot live and grow because 　14 speaks it.

A living language, of course, is often spoken by people today. It grows and changes with time. New words are created, and some old words have 　15 meanings.

1. A. because 　　　　　　 B. since 　　　 　　　 C. when 　　　　　　 D. as

2. A. out of 　　　 B. back from　　　　 C. away from 　　　 D. back to

3. A. It　　　 　 B. This　 　　 　　　 C. That　 　　 D. He

4. A. each other 　 B. another　 　　　 C. the other 　 D. others

5. A. how long 　 B. how far away　 C. how many 　　　 D. how old

6. A. why　　 　　 B. which 　　 　　　 C. how　 　　 D. what

7. A. each　　　　　　　　　　 B. every 　　 　　　 C. all　 　　　 D. some

8. A. show　 　　 B. say　 　　 　　　 C. talk　 　　　 D. speak

9. A. everything　 　　　 B. something 　　　 C. nothing　 D. anything

10. A. put　　　　　　　 B. drop　 　　　　　 C. fall　 　　　　　　 D. set

11. A. give　　 　 B. put　　 　　　　　 C. show 　　 D. take

12. A. that　　 　　 B. which　 　　　 C. what　 　　 D. why

13. A. send　　 　　 B. bring　　 　　　 C. push　 　　 D. get

14. A. someone 　 B. no one　 　　　 C. anyone 　 D. everyone

15. A. new　　　 B. right　　 　　　　 C. real　 　　 D. good