影响苯汽提塔稳定的因素有（）。
A、液位计失真
B、低压蒸气压力波动
C、反萃取己水带苯严重
D、反萃取塔界面波动大
参考答案：A, B, C, D
对春秋时期的叙述不正确的一项是
A．周天子失去往日权威
B．春秋第一霸主是秦穆公
C．楚国向中原扩张中的对手是晋国
D．曾经问鼎中原的是楚庄王
句型转换。
1. Is it in the backpack?(作否定回答)
________,it ________.
2. Tom's maths book is on the floor.(对画线部分提问)
________ ________ Tom's maths book?
3. His baseball is under the table.(改为一般疑问句)
________ ________ baseball under the table?
4. His dresser is next to his bed.(改为否定句)
His dresser ________ ________ next to his bed.
5.My keys are on the sofa.(对面线部分提问)
________ ________ my keys?
