1._____he had many classmates during the school years,he has almost no friends now.
A.While B.When C.If D.Unless
2.He has become_____to living without electricity.There was no power while he was young in the countryside.
A.content B.accustomed C.independent D.optimistic
3.This is the first group photo _____of these baby pandas in Chengdu.
A.to take B.taking C.being taken D.taken
4.---Any information about your son?
----No,if only I____those tough words to him.
A.hadn't said B.didn't say C.shouldn't have said D.couldn't have said
5.After studying in US for many years,Mary's brother____his job as a doctor.
A.set out B.took over C.took up D.set up
参考资料:剑桥高级学习词典,牛津高阶英汉双解词典