问题补充：
your help, we complete the work in time.
A. Thanks to; were able to
B. Thanks to; could
C. As; would
D. Because; had to
答案：
(答案→)A. Thanks to; were able to
B. Thanks to; could
C. As; would
D. Because; had to
解析：thanks to相当于because of,此短语可放在句首或句尾，to是介词，后接名词、代词或动名词，而as或because后接的是从句，因此排除C、D，其次，当表示过去有能力并实际上成功地做到某事，要用“was/were able to”不用could，没有做到可用couldn’t或wasn’t/weren’t able to.
