嘌岭碱基的氮原子分别来自于N1(),N3(),N7(),N9();嘧啶碱基的氮原子来自于Nl(),N3()。
参考答案:Asp、Gln、Gly、Gln、NH3、Asp
Can you make sure _____ the key of her flat? [ ]
A. whether Alice had put
B. where had Alice put
C. where Alice has put
D. where has Alice put
用户接入Internet的入口点是()
A.ICP
B.ISP
C.局域网
D.电话网