“无效”造句
如果可的松
无效，我恐怕只能动手术了。
If the cortisone doesn't take, I may have to have surgery.
令人震惊的是，这种既
无效又危险的手术直到20世纪30年代才被废止。
Shockingly, this useless and dangerous surgery did not end until the 1930s.
一份官方法令宣布在首都举行的投票
无效。
An official decree invalidated the vote in the capital.