带负荷运转时应经常检查油水温度变化，保持油水充足，在风扇工作时，避免使温度忽高忽低，柴油机正常工作温度保持在（）以上为宜。
A. 60℃
B. 80℃
C. 70℃
D. 100℃
查看答案
在居民小区中应重点推广（）洗车技术。
A. 高压水枪
B. 无（微）水
C. 循环用水
D. 中水
伸出屋面管道根部四周应增设附加层，宽度和高度均不应小于（）。
A. 200mm
B. 250mm
C. 300mm
Which statement is true about the comparison of voice traffic with video traffic？（）
A. video conferencing traffic tends to be much more bursty in nature and is more prone to have an impact on other traffic flows
B. latency requirements are less stringent for video traffic than for voice traffic
C. video traffic is less sensitive to dropped packets than for voice traffic
D. video traffic requires the retransmission capabilities of TCP whereas voice uses UDP
E. video traffic tends to be much more bursty in nature and is more prone to have an impact on other traffic flows
F. voice traffic requires the retransmission capabilities of TCP whereas video uses UDP
微信支付 
支付宝支付