1、All living things on the earth need other living things to live with. Nothing lives 36 . Sometimes one living thing kills 37 . Each kind of life eats another kind of life 38 live, and together they form a food chain(食物链). Some food chains are simple, while others are not. But 39 food chains begin wi
2、th the sun, and all food chains become 40 if one of the links disappears.All life needs sunlight to live on. But only plants can use 41 directly(直接地 ). They make food from sunlight, water, air and so on. Animals can only use the suns energy 42 it has been changed into food by plants. Some animals fe
3、ed directly on plants. Others eat smaller animals. Meat-eating animals are only 43 plants indirectly.What about human beings? We are members of many food chains. We eat wheat, rice, vegetables, fruit and so on. We also eat meat and drink milk. But 44 often break up the food chains. They kill wild an
4、imals. They also make rivers, lakes and seas dirty. When these rivers, lakes and seas are polluted, the fish in them 45 be eaten. If people eat the fish, they will get strange diseases. Each form of life is linked to all the others. Breaking the links puts all life in danger.36. A. alone B. lonely C
5、. together D. happily37. A. other B. the other C. another D. the others38. A. for B. so that C. and D. in order to39. A. any B. all C. some D. most40. A. better B. broken C. stronger D. nicer41. A. moonlight B. laser light C. sunlight D. bright light42. A. after B. before C. until D. by the time43. A. making B. catching C. eating D. feeding44. A. sunlight B. animals C. plants D. people45. A. can B. cannot C. must D. neednt36-40 ACDBB 41-45 CACDB
