再生障碍性贫血时为防止出血过多应输（）
A.浓缩红细胞
B.血清
C.红细胞
D.血小板
E.血浆
参考答案：A
已知在一定条件下3分子乙炔可发生加成反应生成苯：
试预测下列物质3分子加成后的产物。
(1)3H—C≡ (2)3
It was only after he had spent several nights digging around the cross ________ he decided to write to Kit Williams to find out if he was wasting his time there.
A．that
B．how
C．and which
D．what
(2)3 