-How many passengers were in the plane?-It ______ 227, 153 people from the Chinese mainland and one from Taiwan ______.
The doctor will not perform the operation ___ it is absolutely necessary.
Difficulties are nothing ___ we are not afraid of them.
―When do we need to pay the balance ? ― September 30.
I'd like to go swimming ____ the water is not too cold.
It’s quite me why such things have been allowed to happen.