几道高中英语题,求详解,拜托各位了!

几道高中英语题,求详解,拜托各位了!
1.it is fairly common in africa for there ___ a group of musicians surrounded by others.
A.are B.be C.being D.to be
答案是D
2. My consideration ___financial crisis in the USA has heavily influenced our country
A.which B. if C.what D why
答案D
3.Milions of pounds's loss __by the storm which swept acrossthe east of England last night .
A.had been caused B.was caused C.has been caused D.would be caused
4.____U2 ,the Irish rock band from Dublin perform a concert in Beijing ,tell me advanced.
A.If B.shall C. should D.would
答案c