It will be 2 years _______ we see each other again.

—Why do you like staying in Guiyang?—Because the weather there is _____ too hot _____ too cold.

Dad doesn’t want to sell the car. ______the car is old, it still runs well.

Nothing can be done _______  he returns.

The rivers will become dirtier and dirtier _______ we take action to protect them.