Question

Though it is very difficult ,we will finish the work in time---------

A at a lss B at any rate C at once D at all event 求解释谢谢 bd有什么区别？
为什么选b

Answer 1

初看这道题目,我和你有相同的疑问，因此我特地查询了美国成语大辞典。
At any rate=in any case, anyhow. It is not much of a car,but at any rate it was not expensive.
At all events=in any event=in any case=anyhow=anyway, it may rain tomorrow,but we are going home at all events.
从上也证实了我的疑惑，那就是这题目有问题，就成分而言都是副词成分，就意思而言他们是同意词替换，bd没有根本区别，你的理解是正确的

Answer 2

at any rate，无论快慢
at all event是总之，无论如何的意思
尽管困难重重，我们无论如何都会及时完成工作。

Answer 3

尽管这很困难,但我们仍要及时完成工作(尽管及时完成工作很困难,但我们仍要努力去做)