Perhaps the day will come ____ people willbe able to breathe clean air in cities

Larry, I will call you at 6 o’clock tomorrow morning.—Thanks, MumBut it’s too earlyI _____then

Now, children begin to learn English at avery early age. It is really a good thing—_________.

He’s late, __is often the case

Some passers-by witnessed the car accident____ five passengers were killed, a baby included.