建设“三北”防护林工程的最主要目的是[ ]
A．调节气候，美化环境
B．净化空气，吸烟滞尘
C．防风固沙，防止水土流失
D．为野生动物提供栖息地
答案：C
Hamburgers are very delicious, ______ they are not healthy. [ ]
A. but
B. because
C. or
D. so
前八后五
