If the police would have arrived earlier, he would have seen the accident.
would have应改为had[解析] 当表示与过去事实相反的虚拟假设时，从句谓语要用“had+过去分词”的形式。
举一反三
- He said the driver must have had an accident, otherwise he _____ by then. A: would arrive B: should arrive C: must have arrived D: would have arrived
- I_____ much earlier if I had not been caught in the traffic. A: have arrived B: will have arrived C: arrived D: would have arrived
- He must have had an accident, or he ______ himself（ ）. A: had to be B: should be C: would be D: would have been
- He must have had an accident, or he ______ here then. A: should be B: B. would be C: could have been D: D. would have been
- If he had taken Flight 307, he( )now. A: arrives B: would arrive C: would have arrived D: arrived
内容
- 0
Had he come earlier, he()my brother. A: would meet B: shall meet C: shall have met D: would have meet
- 1
Not until the play had begun ______at the theatre. A: had he arrived B: did he arrive C: would he have arrived D: should he have arrived
- 2
Not until the game had begun __________ at the sports grounds. A: did he arrive B: had he arrived C: should he have arrived D: would he have arrived
- 3
Jim __________ yet, otherwise he would have telephoned me. A: mustn’t have arrived B: shouldn’t have arrived C: can’t have arrived D: need not have arrived
- 4
Jack ______ yet, otherwise he would have telephoned me. A: mustn't have arrived B: shouldn't have arrived C: can't have arrived D: need not have arrived