单项选择题

The author thinks that ______.

A．it is impossible that we encounter some alien form of life
B．life only exists on Earth
C．it is likely that we'll encounter some alien form of life
D．beings from outer space will never visit the earth

<上一题目录下一题>

热门试题

单项选择题

Which of the following is NOT among the four possibilities of why we haven't been visited

A．Forms of life on the other planets don't evolve to intelligent beings.
B．Earth is the only planet that contains life in the universe.
C．life on the other planets destroys itself
D．Beings from outer space are too far away from us.

单项选择题

What does the word discount (line 6, Para. 1) most probably mean according to the context

A．Doubt
B．Accept
C．Discharge
D．Disregard