单项选择题

The aim of the voyages Maury was responsible for in the 1840 was ______.

A．to make some sounding experiments in the oceans
B．to collect sample of sea plants and animals
C．to estimate the length of cable that was needed
D．to measure the depths of the two oceans

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热门试题

单项选择题

People tend to ignore the delayed effects of exposure to chemicals because

A．limited exposure to them does little harm to people's health
B．the present is more important for them than the future
C．the danger does not become apparent immediately
D．humans are capable of withstanding small amounts of poisoning

单项选择题

Which of the following is closest in meaning to the sentence Man, ...is part of nature. (Line 3-4, Para. 1)

A．Man appears indifferent to what happens in nature.
B．Man acts as if he does not belong to nature.
C．Man can avoid the effects of environmental pollution.
D．Man can escape his responsibilities for environmental protection.