Would you like________ the environment?—I don’t know. What can I do?[ ]
Some people fear that ______ air pollution may bring about changes in ______ weather around the world.
Jim is good at maths, but his physics is _________.
A student _________ from a tree and __________ his right leg.
What are you doing there?—I’m going hiking _______ the mountains. I like going there _______ vacation. [ ]