Environmentalists in the developed countries also worry about air pollution in poorer countries because ______.
A. they are very kind-hearted and care much about the people there
B. they are afraid that more people will immigrate into their countries
C. they know that governments there are not taking effective measures to deal with the problem
D. they fear that the pollution there may cause harm to their own countries
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What is the possible meaning of "abolitionists"(Line 3, Para. 1)？
A. Free black people.
B. Aggressive white people.
C. Those who were against slavery.
D. The leaders of the organization.
The passage is intended to convey that the effect of immigration on natives' wages is ______.
A. uncertain
B. persistent
C. inconclusive
D. insignificant
What statement is true according to the passage？
A. You should write a long and detailed email so that others can get a clearer picture of what you want.
B. You can beg for sympathy so that others can give you more items.
C. The taker can be informed of the pickup time by the giver on the website.
D. You can make friends through the Freecycle group.
Who, as a black conductor, made the greatest contribution to black slaves' escape？
A. Quakers.
B. W. H. Siebert.
C. Harrit Tubman.
D. Unclear.
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