—Have you got used to the Chinese food, Robert?—Yes, but I don't like ________ when a Chinese host keeps serving me the food I don't like.
--How often do you drop your English teacher a line? ---________. But usually once a week.
Some English scientists are identifying problems ____ technology in the 21st century. If solved, the solutions could change the world.
Exactly ____they did when at last they reached the sea remains a complete mystery.
One thing’s for sure, the fire _____by some cigarette butts.
You could ________ this a really nice room if you bought a new carpet.