英语题目在线解答?

1,

正确选项是A.wasn't。We could have walked...这是用了虚拟语态，表示对过去事实的虚拟（说话人“过去”事实上没步行去车站，而是乘坐taxi，现在有点后悔，因为车站很近）。所以答话人用的也是虚拟语态，对现在事实的虚拟，用过去式wasn't（他们坐了taxi，用虚拟语态说“坐taxi是完全没必要的”）。

如果是D,那题目应是:
We could have to walk to the station; it was so near. —Yes. A taxi ______ at all necessary.
是一般现在时态.

2,

- What have you been doing recently?
- I ( A )a trip to Australia and have just returned.
A. took B. have taken C. had taken D.have been taking.

"We could have walked to the station,it was so near"
"Yes,A taxi( B )at all necessary."
A.wasn't B.hadn't been C.wouldn't be D.won't be

1.could have done是本应该做某事的意思（实际上没有做）。
所以We could have walked to the station,it was so near的意思是车站那么近，我们本可以步行过去的。（实际上没有步行去，而是搭了taxi）
回答坐taxi根本没有必要，是指过去的事情，所以选A
2.and前后要保持时态一致，所以要用现在完成时，选项只有BD，但是take a trip不是持续性的动作，只能选B。如果D选项是have been on则也是正确的。

A C

上面那个是A选项，COULD HA