at / by the end of, in the end 的区别：
1.at the end of +时间点或地点,意思是,“在…的尽头,在…的末尾”
eg:They will havesportsmeeting at the end of March. (时间)
He put some books at the end of the bed. (地点)
2.in the end “最后,后面不跟名词”,是个句子成分,可修饰整个句子.（貌似没有in the end of 吧)

eg: They wanted to find a place to rest in, in the end, they saw a village
3.by the end of +时间点,“截止到…末,到…为止”
若接过去的时间点,常用过去完成时： We had built ten buildings by the end of 2002.They had planted six thousand trees by the end of last month.
若接将来的时间,常用一般将来时：We shall finish the work by the end of next month.

为什么不用陈述句呢?这是最常用的语序.陈述句一般结构：主语+谓语+宾语.
.o~~那.--- ___________ great fun it is to fly kites! ________ fantastic time the children are having!--- Yes, I agree. A. What, What a B. What, What C. How, How a D. What a, What应该选什么呢。。为什么呢、。选B。 应为fun和time均为不可数名词。 what是疑问代词，what+a/an+adj.+n.+主+谓。 what+adj.+n.(不可数or名词复数)+主+谓。 eg:What a funny day it is.how是疑问副词，how+adj.\adv.+主+谓。How fun it is.