骑士文学反映的是骑士精神，一般指哪个阶层的人员？（）
A、骑士阶层
B、贵族阶层
C、国王
D、以上都
参考答案：D
There are a lot of students in the classroom. Some are reading and some are _____.[ ]
A. write
B. writting
C. written
D. writing
幽门梗阻所致的呕吐常发生在
A．餐后立即呕吐B．餐后1小时内呕吐C．餐后数小时呕吐D．活动后呕吐E．体位改变时呕吐
