请帮帮忙作一下下面的选择题,解释一下,并说明理由!

请帮帮忙作一下下面的选择题,解释一下,并说明理由!
1.In such dry weather the flowers will have to be watered if they___.
A.have survived B.are to survive
C.would survive D.will survive
2.Hand in hand with reading, he had___thehabit of making notes.
A.developedB.invented C.made D.built
3.I came to___in the end why this must be done.
A.understood B.realizeC.follow D.get
4.Who is he?
A man___himself Smith.
A.namedB.who is calledC.callingD.calls
5.His spelling is poor but he is very___figures.
A.slow B.quickC.quicklyD.slowly
如能回答这些问题,感激不尽!
请一定说明理由!谢谢!!!