$28. There are still many problems ______ before we are ready for a long stay on the$
Moon.
Answer key
D
There are still many problems…——2014 高考英语第 9 题答案解析
2014_北京卷 (英语)
题目指纹
这道题真正考什么？
关键能力
单项填空
difficulty
Differentiating
2014_北京卷 (英语)
$28. There are still many problems ______ before we are ready for a long stay on the$
Moon.
D