1.with his attention ( ) on the job ,he did noteven look up when we came in A focused B focusing C to focus D having focused为什么选A 不选B 2.The lady ( ) thirty poor students go to college by the end of last year.A helped B had helped C has helped Dwould have helped 为什么选B不选C分析分析.3.( )all of the questions have been settled ,you can go on with your workA only if (除非..才) B even though (即使) C now that (既然,由于) D what if(倘使...将会怎样;即使...又有什么要紧)我查了意思.为什么选C不选A

1. 考查“with+名词/代词+动词ing分词/动词ed分词/to do”，解题思路就是理解题干意思，若表目的、将来，则用to do形式；若不是，则考察该结构中动词与with后的名词或代词的关系，若为主动关系，则用动词ing分词；但若为动宾关系（即被动关系）则用动词ed分词。联系“把某人的注意力集中于某事”的英语表达“focus one's attention on sth” 可知，此处应用focused.
2. 选项B与C的区别在于参照的时间点不一样，现在完成时是参照现在而言的；而过去完成时则是参照过去某个时间；故此题关键在于发现时间的参照点。从题干中的时间状语by the end of last year（到去年结束时）可知参照的时间点是过去，故用过去完成时，而不用现在完成时。
3. only if 意为：“只有”。Only 修饰状语位于句首时，主句需部分倒装。若选A，其后的句序应改为can you go on with your work. 如：On in this way, can we study English well. 故不能选A，而选C。

focus one's attention on 所以with attention focused on (被动）
by the end of +过去时间 和过去完成时连用
+将来时间 和将来完成时连用
A 主句需要倒装

1.with his attention ( ) on the job ,he did noteven look up when we came in A focused B focusing C to focus D having focused“注意”是被集中到工作上,所以要用过去时2.The lady ( ) thirty poor students g...