He let me repeat his instruction ______sure that I understan

1.He let me repeat his instruction ______sure that I understand what was ______after he went away.
A to make ,to be done B.making,doing
C to make ,to do D making ,to do
为什么选A不选C呢
答：be to+V = will/shall/ be going to/ should/must+V
what was to be done= what should be done; what was to do= what should do
如what 后没有这个was,则C就可以了：I understand what to do...= I understand what I should do.
2.The building ________day and night______the students' dormitory
A built,will be B to be built ,will be C being built ,will be Dbuilt ,was
选C是为什么 不选D么
答：这个day and night表示日日夜夜,
句意：这幢夜以继日正在建造的大楼将是学生宿舍.
D.是最不好的选项.因为built 表示“被动且完成”,与day and night搭配不当,且was用得也不好.表示“过去是”,有“现在不是,挪作他用了”的意思.
但B选项勉强也说得通的.to be built =which will be built,句意：那幢将要被夜以继日地进行建造的大楼将是学生宿舍.
3.Entering the office,she found the boss ______by papers and letters and_____worried.
A surrounded,looked B surrounding ,looking
C.surrounded,looking D,surrounding,looked
为什么选C不选A呢
答：She found the boss后有两个宾语补足语,一个是过去分词,表示这老板是被文件和书信包围住了.第二个是现在分词looking worried 表示这老板看上去很烦恼的样子.The boss looked worried.老板与look之间是主动关系,用现在分词,look是系动词,没有被动语态,所以不能用过去分词.原句相当于:She found the boss surrounded by papers and letters and she also found the boss looking worried.
当然,你可以说and后的looked worried是与found 并列的,=She found the boss surrounded by papers and letters and she looked worried.但你翻译一下,句子意境好吗?

NO1; to make 表示目的，to be done表示事情是被做的对象，因而用被动语态。
NO2;C表示被动进行，D如果将was改为is也正确

第二题第一空表示正在 儿第二空表示将要 如用过去式则表示过去，不符合语境 第三题中考非谓语 第一空老板被书包围雇佣ed第二空中ing表示动作与主语同时发生或几乎同时发生 而主语为she ．enter与look都是主语的动作 故用现在分词...

第一题A选项to make 是表示目的，可以理解为“为了确保”，第二空是不定式表将来，而整个句子是过去时，所以，应该用过去将来完成时
第二题“这座正在日夜赶工建设的建筑将成为学生宿舍”。day and night 一般表示夜以继日的工作，而整个句子中也没有完成时，所以可以推测楼正在建，因此不选D...