Since 1939, numerous scientific studies ______. A: proved smoking causes fatal diseases B: proved smoking causes life-shorting diseases C: proved smoking is a health risk D: had been made to prove whether smoking causes life shorting

Air transport is not suitable for transporting __________。( ) A: bulk cargoes B: fresh flowers and fruits C: goods with shorting selling life D: high value, low volume merchandise

The semester is _____ because of the cronovirus pandemic outbreak. A: shorten B: shorting C: shortened D: short

十进制数(74.5)10转换为十六进制为(<br/>)。 A: shorten B: shorting C: shortened D: shortened

10.In the novel, Dorian Gray’s life can be summarized as _____. ? empty life;|double life|vain life|immoral life

人生没有朋友，犹如人生没有太阳。 A: A life have no friend is a life have no sun. B: A life without a friend is a life without a sun. C: A life having no friend is a life having no sun. D: A life without the friend is a life without the sun.

Once you have made a friend, it’s a friend ______. A: for life B: in life C: on life D: for a life

The bioethics which believes that human life is supreme, sacred and inviolable value is A: The sacred theory of life B: Theory of quality of life C: Life value theory D: Life Supremacy

（Multiple Choice）Which period of life does choice have the greatest impact?（ ） A: earlier period of life B: middle period of life C: later in life D: end of life

One of the many meanings for天is nature, and nature consists of ____ A: life form B: non—life form C: life and non—life forms