Whenever the alarm clock rings in the morning,I yawn,stretch,and roll over for another five minutes of sleep.(一般现在时)
The following Tuesday I raced home from school,put the bag over my shoulder,dumped the magazines in and embarked on the highway of journalism.(过去时)
On the one hand,the government will do what it can to hunt for the hackers(黑客)and ,on the other hand,internet users will have to learn how to protect themselves.(将来时)
In the past,most families in
He broke his leg in the accident,and according to the doctors,he will never be able to walk again.(过去时和将来时)
Many people believe that morning exercises do them a lot of good.
He thinks that it will rain tomorrow.
We know that we have missed an opportunity and that it may never come again.
I am in good shape because I used to do a lot of exercises.
He says that they are working on a new model of Boeing(波音飞机).
Scientists have studied the universe ever since telescope was invented.40.若主句动词为过去时，从句动词一般为过去时或过去完成时，情态动词也要相应地改成过去时。引导间接引语的动词是过去时态时，也要用时态呼应的规则
Centuries ago,people held a belief that the sun moved around the earth.
He thought that it would rain the next day.
He had done all that was necessary.
By the time they found the hacker,he had already broken into the computer system of the bank.
I got the job because I was a good driver.(并不表示我现在就不是好司机)
I wanted to join the police,but I wasn’t tall enough.(不表示我现在就高了)
I’ll write to you as soon as I finish/have finished the final exams.
The workmen will have completed their repairs by the time the airport is reopened.