单项选择题

It can be concluded from the passage that ______.

A．the Grand Canyon was formed by the internal pressure of the earth and the corrosive force of the river
B．the Grand Canyon was formed by different natural forces
C．the Grand Canyon was formed by the Hulapai River and the Colorado River
D．the Grand Canyon was formed by the corrosive force of the river and other factors

<上一题目录下一题>

热门试题

单项选择题

Which of the following statements may lead to family quarrels according to the passage

A．Unawareness of energy cycles.
B．Familiar monologues.
C．A change in a family member' s energy cycle.
D．Attempts to control the energy cycle of other family members.

单项选择题

If a person finds getting up early a problem, most probably ______.

A．he is a lazy person
B．he refuses to follow his own energy cycle
C．he is not sure when his energy is low
D．he is at his peak in the afternoon or evening