___ the _____ of modern industry, thepollution is becoming more and more serious.

We don’t know __________ he can make a plane byhimself. It is amazing.

The English play _____ my students acted at the New Year’s party was a great success.

Excuse me , ______ you take a photo for us— Sorry, I can’t.

the safety of gas, the government has checked the city’s gas supply system thoroughly.[ ]