根据录音，选择合适的答案（） 查看材料
A. Reading books．
B. Doing fire drills．
C. Watching videos．
D. Taking courses．
根据录音，选择合适的答案（） 查看材料
A. Looking for something to cover the face．
B. Taking slow breath to take in less smoke．
C. Wetting the clothes or the body to keep cool．
D. Running towards the exit as fast as possible．
根据录音，选择合适的答案（） 查看材料
A. On every continent but not in every country．
B. On the continents with developed countries．
C. On the continents with developing countries．
D. On every continent and in every country．
细胞凋DNA 链断裂的主要部位是()。
A. 富含AT的区域
B. 富含GC的区域
C. 核小体之间的连接
D. 已经发生DNA损伤的部位
E. DNA的任何区域
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