食管裂孔疝主要病因是（） A.LES功能减弱 B.胆汁反流 C.食管对酸清除作用下降

读短文，判断正(T)误(F)。

      I like school days, because I can learn (学习) many things from school. We have four classes in the

morning and two in the afternoon. I like weekends, too. We don't go to school on Saturdays and Sundays. I

often play ping-pong and basketball on Saturday morning. I often play the violin (小提琴) on Saturday afternoon.

I often do my homework and play football on Sunday morning. I often go to the park on Sunday afternoon.

( ) 1. I go to school five days a week.

( ) 2. We have four classes every day (每天).

( ) 3. I play the violin on Saturday afternoon.

( ) 4. I like Saturdays and Sundays.

( ) 5. I often do my homework, play football and go to the park on Sundays.

起重指挥人员、起重机械操作人员和司索人员须取得国家政府主管部门颁发的、有效的（）后，方可从事指挥和操作。

心电图中代表心室复极化过程的是( )

A．P波
B．QRS波群
C．T波
D．PQ间期
E．ST段

持续颈椎牵引的重量通常为()

A．5kg

B．10kg

C．15kg

D．20kg

E．25kg

对于已经专业定向的中职生来说，更应该加强培养对即将从事的职业的兴趣。