It is reported that in our country cities ________ heavy air pollution that is 30 percent above the national standard or higher should try to meet standards by 2030.

A．suffering

B．suffer

C．suffered

D．are suffering

If you know the two sentences are different _____ each other, you had better

tell us the difference _____ them.

A．between; from

B．from; between

C．from; from

D．from; with