Questions 3 and 4 are based on the news report you have just heard.浏览器不支持音频
A. To end the one-child policy.To encourage late marriage.
B. To encourage late marriage.
C. To increase working efficiency.
D. To give people more time to travel.
查看答案
Questions 1 and 2 are based on the news report you have just heard.浏览器不支持音频
A. He set a record by swimming to and from an island.
B. He celebrated his ninth birthday on a small island.
C. He visited a prison located on a faraway island.
D. He swam around an island near San Francisco.
Question 2 are based on the news report you have just heard.
A. He doubled the reward.
B. He cheered him on all the way.
C. He set him an example.
D. He had the event covered on TV.
对细胞周期检查点的表述不正确的是()。
A. 检查点是一类负反馈调节机制,构成了DNA修复的完整元件
B. 通常细胞周期有四个重要的检查点:G1/S期检查点、S期检查点、G2/M期检查点和M期检查点
C. 检查点在维护基因组稳定性方面非常重要,它保证了在细胞周期中上一期事件正确完成之后下一期的事件才能开始
D. G2期检查点控制着细胞增殖活动的进程,是细胞增殖与否的转折点
下列对细胞周期的特点描述不正确的是()。
A. 只能沿G1→S→G2→M方向推进而不能逆行
B. 各期细胞形态和代谢特点有明显差异
C. 不受细胞微环境影响,也不与细胞外信号、条件等相关。
D. 存在检查点并在一定情况下决定细胞下一步的增殖分化趋向
微信支付 
支付宝支付