─ Do you drink much coffee as before?
─ No, at all. My sleeping problem is getting worse.
A:none
B:little
C:nothing
D:anything
The sun was shining brightly, everything there more beautiful.
下列词语中划线的字注音正确的一项是( )
调查自己班里的同学1分钟跳绳的成绩,并作图,与小敏的调查结果对比,谈谈有什么不同?
若用两种识别切割序列完全不同的限制酶E和F从基因组DNA上切下目的基因(1.2kb,1kb=1000对碱基),并将之取代质粒pZHZ1(3.7kb)上相应的E—F区域 (0.2kb),那么所形成的重组质粒pZHZ2