In the geography class, the teacher explained wind and water might cause soil()
A. pollution
B. excellence
C. explosion
D. erosion
DNA指纹的遗传学基础是()。
A. 连锁不平衡
B. DNA的多态性
C. 串联重复序列
D. MHC的限制性
E. MHC的多样性
构建打靶载体一般需要通过几次DNA体外重组过程?()
A. 1
B. 3
C. 5
D. 6
E. 7
Lots of birds were flying among the trees branches. What a(n)()view!
A. explosive
B. amused
C. amazing
D. terrified