（题文）Beijing’s new international airport ___________ into use in 2019 will serve 72 million passengers annually.

I think your mother is_____you at the school gate at the moment.

I have got a headache.—No wonder.You___in front of that computertoo long.

Research shows that though students benefit from having parents involved at school, _____ happens at home matters much more.

__________ the heavy fog, our flight was held up eventually