管子板牙的规格有()。
A.一种
B.两种
C.三种
D.四种
参考答案:B
连词成句。
1. a of map here is China
.
2. two about it's kilometres thousand
3. far it is how to from here city your
?
4. are by we train going
5. too is this dress big
某双链DNA中已知一条链中A=30%,G=24%,其互补链的碱基组成是
A.T和C 46%
B.A和G 54%
C.A和G 46%
D.T和C 60%
E.T和C 54%