The method recommended by WHO is in accuracy, but it is too demanding in operation and it consumes too many laboratory animals.
They are living with their parents for the moment because their own house _______.
It was so dark in the cinema that I could hardly ______ my friend.
—Time is limited. I have to finish this tonight. —But it’s midnight now and you should have a sleep ______ much work you have to do.
—Robert is indeed a wise man. —Oh, yes. How often I have regretted ______ his advice!
Occasions are quite rare _______ I have the time to spend a day with my kids.