题目

下列四个图示中，能正确表示染色体、DNA、基因三者在概念上的大小关系的是(   )A                 B                 C                 D 答案：B解析:染色体由DNA和蛋白质组成，每条染色体含有一个DNA分子，每个DNA分子上有许许多多决定生物性状的片段，叫做基因。Some of my classmates are not feeling well. Tom has a toothache. He can’t eat anything. Jack has a bad headache. His father asks him to lie down and rest. So he doesn’t go to school today. Peter is stressed out, because the exam is coming. Nancy has a stomachache because she ate too much yesterday. So she couldn’t eat anything today. Jim has a headache and he is stressed out, too. Lucy has a cold and toothache. She will see a dentist this afternoon.【小题1】What’s the matter with Tom?A. headache       B. toothache   C.stomachache【小题2】Why doesn’t Jack go to school?A.his mother asks him not to go.B. the doctor asks him not to goC. he doesn’t feel well.【小题3】What food can Nancy eat?A. apples          B. nothing.           C. chips【小题4】Who is stressed out?A. Peter           B. Jim               C. Peter & Jim【小题5】What should Lucy do?A. Drink some waterB. eat chocolateC. Listen to music