等效养护龄期应根据同条件养护试件强度与在标准养护条件下()d龄期试件强度相等的原则确定。
A.7
B.14
C.28
D.21
参考答案:C
_________ are good friends. We often play together.
A.Jill and I
B.I and Jill
C.Jill and me
D.Me and Jill
卵受精后的早期几轮细胞周期中无()
A、DNA复制
B、转录活动
C、翻译活动
D、翻译后修饰