--Can I help you? --I'd like to buy a present for my father's birthday, ___________ at a proper price but of great use.
We laugh at jokes,but seldom about how they work.
_____ playing dumb with teachers. They know very well their students.
They thought my suggestion reasonable _______a few experts to help them.
_____but he still couldn’t understand the logical connection of the two subjects.
It was not until he came back _____ he knew the police were looking for him.