单项选择题 Roads in this mountain area used to be（）；people found it hard to travel here.

单项选择题 On May 30th, 2010, at（）World Table Tennis Championship, Ma Lin and Zhang Joke won the gold medal in men’s with（）score of 3:1.

单项选择题 （）from space，the earth，with water（）seventy percent of its percentage，looks like a “blue ball.”