胚胎甲状舌管咽端遗迹为（）。
A.舌盲孔
B.舌背
C.舌根
D.甲状腺峡部
E.舌体
参考答案：A
—Did you catch the early bus this morning?
—No. It had left the stop________I arrived there.[ ]
A. as soon as
B. as the time
C. by the time
D. during the time
什么水平的动机最有利于达到高效率（）
A.高
B.适中
C.低
D.无
