we were playing basketball on the playground, it began to rain.

of them has known about this because it has been already reported on TV.

China supplies more than 90 percent of the world’s rare earth metals, but its reserves only ________ about one-third of the world’s total.

It’s not good for people __________ waste water (污水) into the river.

I think watching __________ TV is bad for our eyes.—Me too.