单项选择题

Smoke particles and other air pollutants are often trapped in the atmosphere, thus forming dirty fog.

A．constrained
B．caught
C．concealed
D．concentrated
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单项选择题
So strange were the circumstances of my story that I can scarcely believe myself to have been a party to them.
A．just
B．hardly
C．almost
D．definitely
单项选择题
Your grade will be based in large part on the originality of your ideas.
A．creativity
B．popularity
C．feasibility
D．flexibility
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