24.\x05He\x05always keeps calm\x05 difficulties an

24.\x05He\x05always keeps calm\x05 difficulties an

B这个介系词表示面对,其余三项不贴切.Cremember后接动词不定式表示动作未做,动作已做,接动名词.D在基数词、neither、all、none、most、one、形容词最高级、一些名词如part、the minority、the majority、the privelege few等后面,常常用of which或of whom来引导非限制性定语从句.因为是在介系词of后面,所以只能用which或whom.而且这里的of whom、of which是不用whose来代替的,在别的名词后的of whom、of which则可以用whose代替.比如：He bought some apples,two of which he gave her.I have twenty-one members in my club,most of whom are girls.John gave several reasons,only a few of which were valid.I met some girls,one of whom is my cousin.The teacher discussed Jim,one of whose problems was poor study habits.I have twenty-one customers,the privilege few of whom can affiord it.It is a family of eight children,all of whom study music.We tested fifteen samples,none of which was completely waterproof.He is looking for a car the engine of which was in good condition.（这句话的the engine of which则可以用whose engine来代替）D先行词被形容词的最高级修饰时,关系代词只能用that,不能用which,少用who、whom.Cinclined后面加动词不定式,表示愿意.Dafford在这里是动词,表示负担得起,后面接动词不定式,其余三项不贴切.D在这里,switch可以表示调换的意思.紧急关头把……视为理所当然盛衰沉浮有规律地,定期地突然与……协调一致好歹提前开始所有其他的事情都是平等的（这是分词的独立主格结构）希望我能帮助你解疑释惑.

感谢回答，我学习了