下列何种是睾酮的活性形式,在男性生殖器官发育上起主要作用( )
A.5α-二氢睾酮B.氢异雄酮C.17-羟孕烯醇酮D.雄烷二酮E.雄烯二酮
参考答案:A
To their great relief, the missing child returned home, ______, after an absence of two weeks.
A.looked tired and healthy
B.tired and healthy
C.tiredly and healthily
D.looking tired and healthily
下列公式用以表示均数抽样误差的是()。
A.
B.s
C.s2
D.
E.CV