The question came up at the meeting ______ we had enough money to do theresearch[ ]

Teachers have to constantly update their knowledge inorder to maintain their professional _____.

The earth will become worse and worse ________ we do something to stop her from being polluted.

In the future,cars won’t be ______,and it’ll be _____to travel everywhere by plane.

Can you believe I had to pay 50 yuan for a haircut?—–You should try the barber’sI go. It’s only 10.