1 she didn't call me last night because she didn't know me phone number -> if........................ 2 they cancelled the trip because it rained heavily -> if.......................

=>

1. If she had known my phone number, she would have called me last night. ( câu điều kiện loại 3: sự việc trái với quá khứ: If+ S+ had+ (not)+ PII, S+ would/ could...+ have+ PII....)

2. If it hadn't rained heavily, they wouldn't have cancelled the trip. ( Giải thích tương tự câu 1.)