异构化反应中，降低氢油比，则（）。
A、催化剂的积炭速度加快
B、PX的转化率提高
C、催化剂的副反应加快
D、乙苯的转化率提高
参考答案：A
正常舌象应为（）
A.淡白舌，薄白苔
B.淡红舌，薄白苔
C.舌淡红，苔白
D.舌淡，苔白
E.舌淡白，苔薄
Not only Jim but also his parents ______ a few places of interest since they came to China.
A．has visited
B．will visit
C．have visited
D．visited
