英语根据词的类型填空 请帮忙讲解一下为什么这么填 谢谢了！

Question

1.When you come to the library at eight this evening ,I _____(study) there.
2.Two hundred more such houses______(build) by the end of the year.

Answer 1

1.When you come to the library at eight this evening ,I _will be studying____(study) there.
2.Two hundred more such houses__will be built____(build) by the end of the year.

第一题为将来进行时，关键词在 at eight ， this evening ，有个具体的时间点，而且是将来时态，所以要用will be 结构
第二题为将来完成时，关键词在 by the end of the year，在今年年底，所以也要用到will be，build 为被动语态，用built

Answer 2

will study 将来时
will be built 将来时 被动
我不知道真确否 仅供参考

Answer 3

1.have been studying 过去进行时have/has been doing sth.
第二个不知道