We cannot figure out ________ quite a number of insects, birds, and animals are dying out.
Though having lived abroad for years, many Chinese still ______ the traditional customs.
----Are you finishing your task? -----_______. We need at least three more hours.
Is having a lot of money important to a woman when it comes to _______a husband?
Hobbies are _______ in helping patients recover _______ physical or mental illness.
The game is rough and injuries are _______to occur.