M基因编码含63个氨基酸的肽链。该基因发生插入突变，使mRNA增加了一个三碱基序列AAG，表达的肽链含64个氨基酸。以下说法正确的是
A：M基因突变后，参与基因复制的嘌呤核苷酸比例增加
B：在M基因转录时，核糖核苷酸之间通过碱基配对连接
C：突变前后编码的两条肽链，最多有2个氨基酸不同
D：在突变基因的表达过程中，最多需要64种tRNA参与
在2015年10月26日召开的十八届五中全会上，我国决定取消独生子女政策，全面实施开放二胎政策。下列说法理解正确的是（ ）
this key is your mother's.
Good morning! Now let me report the discussion work in our group. Wu Jun cleans up rooms ____ weekends and Jia Mei likes cooking dinner with her mum. Wang Ping sometimes ____ (wash) clothes for her family. As for me, I usually help my father water the flowers. In my opinion, it is necessary ____ us students to do some housework by doing it, we can help our parents and understand them better. We’ll also learn to take care of ____ . Besides, we can relax ourselves from hard work and develop our abilities.That’s all. Thanks for ____ ( listen)!
