①分解因式:x2+2x+1=( ).
②若∠ α=40 °,则∠ α的余角是( )度.
(1)(x+1)2;(2)50°
排卵前LH峰()
A.其值小于FSH峰值
B.在促排卵周期中不产生
C.由于雌二醇急剧升高诱发
D.促使颗粒细胞大量生成睾酮
E.诱发排卵立即发生
—What a pity! Their experiment is a failure.
—They ________ better under more favorable conditions.
A.should have done
B.could have done
C.must have done
D.may have done