He would have given you more help, if he ________ so busy.
A、havenotbeenB
本题考察与过去事实相反的虚拟语气。
Itisimportantto________yourskinfromtheharmfulstrongsunlight.
Itrainedhardyesterday,______preventedmefromgoingtothepark.
She has no hostility to us, _____can be judged from her eyes。
It_______methreeyearstodrawthebeautifulhorses.
If the operation ________ carefully prepared, it would not have been successful.
