Your niece is very strict and ______ worth teaching, but your nephew is not. Look, he is now ______ asleep in class.
---He suggests the number of cars should be limited to stop air pollution. --- __________, the idea is not very practical.
.Scientists are trying to develop a special material, _______ they will make use of in space.
The education of _______young is always _______ hot and serious topic in modern society.
_________the authorities continue to crack down football betting _________a new hope in the future.
.—Why, Jack! Someone seems to have called you over there. —Yes? I ________ that.