用if改写下列句子1、One has studied hard,and then the exam is not dif

Tom studied hard and tried _____ the exam. Tom studied hard and passed the English exam (容易). he studied hard,the college entrance exam. （ ）,he would have passed the exam.A.If he studied hard B.Had Jack studied very hard in order not to fail the final exam ( 改错1.He studied very hard .and at the end he passed the exam. He failed in the exam,and I wonder ___ he studied hard in th 英语句子：Mary studied hard only to fail in the exam. The school is being rebuilt.I once studied there (用定语从句改写句子） She studied hard in order to pass the exam She studied hard she studied hard in order to pass the exam =she studied hard To pass the mid-term exam,he studied very hard.开头为什么不可以用Pass