航行警告发布的主要形式有（）。
A、书面
B、无线电报
C、无线电话
D、新闻媒介
参考答案：B, C
外阴基底细胞癌：
A．宫颈粘液结晶B． * * 脱落细胞学检查C．分段诊刮D．宫颈涂片E． * * 镜检查
I believe that those mountains ____ with trees in a few years. [ ]
A. are covered
B. will be covered
C. are covering
D. will cover
