单项选择题

What is the characteristic of the Martian surface according to observations over the past 20 years

A．Remaining stable all the time.
B．Appearing bright red.
C．Looking dark most of the time.
D．Changing from bright to dark or vice vers
<上一题 目录 下一题>
热门 试题

单项选择题
How is the image of the north polar cap of Mars
A．Vague.
B．Clear.
C．Cannot be seen.
D．Barely visibl
单项选择题
Which of the following is TRUE about the north polar cap of Mars in summertime
A．It is at its largest size.
B．It is changing its shape all the time.
C．It is at its smallest size.
D．It is at its windiest tim
相关试题