Air pollution is rising at an alarming rate. It is high time _____. (Complete the sentence)

Physical exercise strengthens both body and mind. If you maintain it consistently, you will keep fit.

They approached you with a view to asking for help, but your harsh reaction discouraged them.

Please wait here until I come back, I have an urgent matter to discuss with you.

I was not hungry at all. If I had been hungry, I would have eaten something.

Forests are indispensable for ecological balance. Therefore, we should plant trees more and more.

There goes evidence that time and tide wait for none. Hence, we must manage our time prudently.