方程组 94
答案:D
由题意知:当x2+x-2=a时,△=b2-4ac=1+8+4a>0,
即a>- 94.
4
故本题选D.
If you write something and send it immediately by email, which you _______ later regret, there is no
chance for second thoughts. [ ]
A. would
B. should
C. have to
D. might
吴先生,近日自觉下腹不适,便稀。今日做肠镜检查。检查结束后对肠镜进行灭菌处理。
应选用的化学消毒剂与浸泡时间正确的是 ()
A.1%增效戊二醛,30min
B.1%增效戊二醛,40min
C.2%戊二醛,30min
D.2%戊二醛,1h
E.2%戊二醛,10h