小儿生长发育最快的阶段是（）
A.新生儿期
B.婴儿期
C.幼儿期
D.幼童期
E.儿童期
参考答案：B
— Do you have any problem in getting accustomed to________in the north?
— Yes. It is too cold in winter. [ ]
A. live
B. living
C. having lived
D. have lived
下面四幅图中都画出了两个力，其中属于二力平衡的是[ ]
A.
B.
C.
D.
