单项选择题 If the feed is introduced at one point along the column shell, the column is divided into an upper section, which is often called  the stripping section, and a lower section, which is often referred to as the rectifying section.

单项选择题 选出单词中画线部分正确的读音 knock A、/m/ B、/n/ C、/ŋ/

判断题 CSMA/CD能完全避免冲突。 正确 错误