虚拟语气的时态：
1.If I were you,I would study hard.(与现在相反的假设,if句用过去时或were,主句用would + 动词原形）
2.If I had studied hard,I would have passed the exam.(与过去相反的假设,if 用过去时,主句用would + 现在完成时）
3.If I should pass the exam,I would treat (招待)you to dinner at KFC.
(与将来相反的假设,if句用should + 动词原形,主句用would + 动词原形）
4.rise vi.(不及物动词,后面不跟宾语)
（太阳、月亮、星星）升起,出现
The sun rose at seven o'clock.
太阳七点钟升起.
5.raise (vt.及物动词,后面要跟宾语)
抬高；举起
He raised his arms above his head.
他把手臂举过头顶.
6.arise vi.(不及物动词,后面不跟宾语)
出现； 发生
That question did not arise.
那个问题没有出现.
起来；站起
I arose early in the morning.
我每天早上起得很早.