How many students are there in the classroom—__________. They are all in the lab.

Did you know any Chinese before you arrived in Beijing?— Never ________ it, actually.

Can you give me ____________ on how to learn English well I need your help.

Every year large quantities of water in the rivers _______ polluted and _______ money is spent solving this problem.[ ]

I could see a low bamboo hut standing there ______ grass sticking out ____ the roof