只能在空气中硬化,并保持或继续提高其强度,属于这类材料的是()。
A.硅酸盐水泥
B.普通硅酸盐水泥
C.硅酸盐大坝水泥
D.石灰
参考答案:D
I would like to ( ) a flight to Paris on January 8 on Air France, First Class and round trip.
A.have book
B.book
C.want
D.have wanted
可用滴制法制备,囊壁由明胶及增塑剂等组成()
A.微丸
B.微球
C.滴丸
D.软胶囊
E.脂质体