亚洲儿童成年身高矮于白种人的主要原因是()
A.气候不同
B.饮食结构有差异
C.文化教育有差异
D.经济水平落后
E.青春期骨骼加快现象
参考答案:E
What troubles her is that she can't buy _____ she wants with the money she earns. [ ]
A. whatever
B. whichever
C. however
D. whenever
直接参与蛋白质生物合成的核酸有( )。
A.mRNA B.tRNA C.rRNA D.DNA