原句：

My teacher advised me to put my heart into my studies.

改写：If I were you, I would put my heart into my studies.

原句：

Regret was wasting so much time meaninglessly.

改写：If I had known the consequences, I would not have wasted so much time meaninglessly.

原句：

I really want you to do better.

改写：If I were you, I would do better.

原句：

He had meant this friend to come to him, but we didn't work hard and failed eventually.

改写：If we had worked hard, we would not have failed eventually.

原句：

He came to help me with a new task ahead of schedule.

改写：If he had come earlier, he would have helped me with a new task ahead of schedule.

原句：

I request to hold another session to discuss the problem.

改写：I should have requested to hold another session to discuss the problem.

原句：

I might have requested to hold another session to discuss the problem.

改写：If I had requested to hold another session to discuss the problem, we would have done it already.

原句：

Coming here please, your idea has been accepted.

改写：If you had come earlier, your idea would have been accepted.

原句：

To win the game, I can get it by every way.

改写：If I were you, I would find a way to win the game.

原句：

If there should be a flood, what should we do？

改写：If there were a flood, we would have to find a way to deal with it.

原句：

If he were here, everything would be all right.

改写：If he were here now, everything would be all right.

原句：

If we were to panic, we would not be able to use nuclear power anymore.

改写：If we panicked, we would not be able to use nuclear power anymore.

原句：

It's said that it's a desert because of nuclear pollution.

改写：If it weren't for nuclear pollution, it wouldn't be a desert.

原句：

If I could swim, I would go to the beach.

改写：If I could swim, I would go to the beach.

原句：

If I had known it was going to rain, I would have taken an umbrella.

改写：If I had known it was going to rain, I would have taken an umbrella.

这些改写句子使用了虚拟语气来表达假设、愿望或建议等虚拟情况，符合虚拟语气的用法。希望这些例子对你有所帮助。