单项选择题 千兆以太网比快速以太网有(29)数据传输率和(30)的碰撞域。

未知题型 听力原文：M：Did you hear that Bob got sick yesterday during the final examination?W：Yes，I did．I think lately he has bitten off more than he can chew in studying and working．Q：What does the woman mean?(14)A．He always eats more than he can chew.B．He eats while studying and working.C．He got sick because he ate too much.D．Bob is trying to study and work too much.

未知题型 下列关于生产安全事故应急预案的实施和奖罚的说法错误的是（ ）。——P256