题目

My brother ________ to college last year, but unfortunately he wasn’t able to take the examination because he was seriously ill.A. needn’t have goneB. shouldn’t have goneC. could have goneD. must have gone 答案：【答案】C【解析】考查虚拟语气。A. needn’t have gone本不需要做某事，实际上却做了；B. shouldn’t have gone本不应该做某事，实际上却做了；C. could have gone本可以做某事，实际上却没有做；D. must have gone一定做了某事；句意：我的哥哥去年本可以进大学，但不幸地是因为生了重病，没有能够参加考试。根据已知p：关于x的方程x2+mx+1=0有两个不等的负实数根，若?p是真命题，则实数m的取值范围是 ．