单项选择题

Exposure to asbestos fibers can cause cancer______.

A．only when asbestos is used in building industry
B．only when it is used in large quantifies
C．even if it is used in small quantities
D．if they are used when wet rather than dry

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热门试题

单项选择题

It can be inferred from the passage that the real danger comes from______.

A．the asbestos dust that people take in
B．the contact of the worker' s skin with asbestos particles
C．the inferior quality of the asbestos itself
D．the excessive use of man-made asbestos material

单项选择题

Louis Brailele designed a form of communication enabling people to______ and preserve their thoughts by incorporating a series of dots which were read by the finger tips.

A．retain
B．visualize
C．convey
D．transfer