平衡型复方氨基酸溶液中,必需和非必需氨基酸的比例一般为()
A.1:2~1:4
B.1:1~1:5
C.1:1~1:3
D.1:2~1:5
E.1:3~1:4
参考答案:C
— _____ I hand in the homework in the morning?
—No, you needn't. You can hand it in tomorrow. [ ]
A. Should
B. Can
C. Must
D. May
下列各地中,年降水量最多的是[ ]
A、赤道地区
B、南极地区
C、北极地区
D、中纬度地区