单项选择题

Scientists say it may be five or six years （） this medicine is tested on human beings.

A．since
B．before
C．after
D．when

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A．Although; on
B．Though; in
C．Despite; in
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A．accounts
B．attempts
C．contents
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单项选择题As is well known, eating too much fat can （） heart disease and cause high blood pressure.

A．add to
B．attend to
C．contribute to
D．apply to