材料一：19世纪60年代，清朝统治者的一些开明官员掀起了一场“师夷长技”的改革运动……

材料二：90多年前爆发的五四运动，是以一批先进青年知识分子为先锋，广大人民群众共同参与的彻底反帝反封建的伟大爱国革命运动……

医疗上用的生理盐水是0.9%的氯化钠溶液．要配制0.9%的氯化钠溶液100g．其中选用仪器或操作正确的是（　　）

A: You must be really excited about leaving for London tomorrow, Judy!

B: Yeah.____

A: Nervous about what?

B : I don't know many of the customs and manners in UK.____

A : Sure.

B:____

A: Well, it's important to be on time when you're invited for dinner.

____ The British expect their guests to be on time.

B: Then how long may I stay there?

A:____ Or you seem to have come only for the meal. When your friends seem to be getting sleepy and running out of things, it's time to leave. The next day, call or write a thank-you note to say how much you enjoyed the evening.

水稻的体细胞中有24条染色体，在一般正常情况下，它的初级精母细胞、次级精母细胞和精子中染色体数目、DNA分子含量，分别依次是（　　）