骨骼肌中横管的作用是 ()
A．Ca2＋的贮存库
B．将兴奋传向肌细胞深部
C．Ca2＋进出肌纤维的通道
D．营养物质进出肌细胞的通道
参考答案：B
用括号里所给词的适当形式填空。每空一词。
小题1:_________________ (woman) Day is my sister’s favourite festival in the year.
小题2:We need to realize the (important) of making full use of our time.
小题3:After lying in bed for three hours, I felt even (sleepy).
小题4:Miss Wang likes wearing _______________ (colour) clothes.
小题5:-- Maths is too difficult. I nearly give it up.
-- Please don’t. Nothing is _______________ (possible) if you put your heart into it.
复合材料聚氯乙烯、聚乙烯、聚丙烯和聚苯乙烯的基体为（）。
A．金属
B．陶瓷
C．热塑性树脂
D．热固性树脂
