Before you pay a visit to a place of interest, look in your local library________a book about it.
The reason _______ he was late was _______ he missed the bus.
The tiger, once a ____ animal to humans, is now ____ of disappearing on the earth.
We shouldn’t spend our money testing so many people, most of ____ are healthy.
I won’t see the film tonight. I am busy. ______, it is raining cats and dogs.
Computersin offices and homes since 1970s.