15.You may ________ the textbook if you don’t know the answer to the question.
Ifto look after luggage for someone else, inform the police at once.
He wrote a letter ______ he explains what had happened in the accident.
Animals are obviously ______ lower form of life than _______ man.
Shethe carpet with some very nice curtains in color.
_______ one of you breaks the window will have to pay for it.