决定你的眼睑是否是双眼皮的物质在（ ）
A．细胞膜上
B．细胞质中
C．细胞核中
D．线粒体中
A、细胞膜是紧贴在细胞壁内表面的一层极薄的膜，能够控制物质的进出．故不符合题意．
B、细胞质不断地流动，它的流动，加快了细胞与外界进行物质交换．故不符合题意．
C、细胞核内含有遗传物质，对生物的遗传具有重要的意义．细胞核内能被碱性染料染成深色的物质叫做染色体，是由DNA和蛋白质组成．基因是染色体上具有控制生物性状的DNA片段．故符合题意．
D、线粒体是细胞内的能量转换器，是呼吸作用的场所，在线粒体里，在氧的作用下，分解有机物，释放能量，供生命活动利用，不符合题意．
故选：C
| 阅读理解。 |
| Dear Victor, I am a college student. Nowadays games on the net are very popular with college students. Some of my roommates aer very intererted in them. They not only play games in their free time, but also keep talking about them at night when lights are off, and they regard games as part of life. I've begged (乞求) them to give it up, but they wouldn't listen to me. It has become a rather big problem. Should I report it to our teachers or do something else? Ted Dear Ted, Drop it. Your roommates, as grown-ups, can do whatever they want with their time so long as it doesn't break school rules or violate (防碍) other people's interests. Playing perhaps gives these students relaxation (放松) from hard study. If they play too often, have little time to study, and they will reap what they have sown, but you will not. Reporting to the teachers would only harm your good name in your dormitory (宿舍). However you have rights to ask your roommates to be quiet when you need sleep. If they aren't angry with you, they will stop talking. But be polite and friendly. Perhaps, in return, join them in a game or two. Victor |
| 1. According to the first letter, many college students enjoy ______. |
[ ] |
| A. playing computer games B. searching information on the Internet C. sending e-mails D. buying things online |
| 2. Ted wants his roommates to ______. |
[ ] |
| A. break their computers B. sell their computers to teachers C. stop playing computer games D. play games in the day, not at night |
| 3. According to the second letter, some college students ______. |
[ ] |
| A. can violate school rules or other people's interests B. have their rights to quarrel with Ted C. can relax themselves while playing games on the net D. can study even better if they play games on the net |
| 4. Victor asks Ted to ______. |
[ ] |
| A. report to the teachers B. harm his good name in the dormitory C. quarrel with his roommates D. learn how to get on well with others |
| 5. In the second letter, the underlined part (划线部分) means ______. |
[ ] |
| A. 自食其果 B. 随心所欲地做事 C. 回家种庄稼 D. 逃避责任 |