He’s never heard to sing a pop song so loudly, ______ he—______. He is so shy.

Flight attendants usually need to arrive at the airport ______ before their flight leaves

The _____ you work at it, the _____ progress(进步) you will make.

elieve spirit stays with the body for3 days, _______someone always stays with the dead person.

Putting in a new window will ______ cutting away part of the roof.