According to the school rules, no student _______ go out of school without the permission of the teachers.
These years China_______a boom in scientific and technological development.
.—Have you finished the work? —Not yet. I _____ to do it just a moment ago.
—How often do you go home to see your parents? —___________, but usually once a week.
_____more and more forests destroyed, some animals are facing the danger of dying out.
David’s effort was ______, because he won the first prize in the English speech contest, _____ made his classmates surprised.