加热炉烟道气氧含量正常,对流段底部形成正压的原因是()。
A、烟道挡板开度小
B、对流段炉管通道堵塞严重
C、加热炉发生了闷炉
D、加热炉的热负荷高
参考答案:A, B
根据背诵内容填空(每空1分,满分5分)
1. The Guinness world record for the fastest _________speed at the Tour de France was set in 1999 by the American ________Lance Armstrong.
2. The woman first bought a few small . After a little time, she one of the most expensive dresses in the shop.
3. Towards evening, the boat ________a rock and the girl jumped into the sea. Then she _______to the shore after spending the whole night in the water.
4. Some of the found in the grave give us an idea of how he was dressed when he was_______.
5. In his _______Frank used to make _______parts for airplanes.
科学计量、工程计量和法制计量是按照计量的( )进行分类的。
A.内容与性质
B.地位与作用
C.特点
D.管理范围