注意：此页面搜索的是所有试题
题目内容
（国家开放大学-开放英语4）
Cycling is a good exercise. ____, it doesn’t pollute the air.
选择一项：
a.
Therefore
b.
Moreover
c.
But
d.
However
选择一项：
a.
Therefore
b.
Moreover
c.
But
d.
However
参考答案
