根据2004年第四次宪法修正案，在爱国统一战线中新增加的社会阶层是（）A．社会主义劳

Scott, please remember to ______ the lights when you leave. [ ]

A. turn on

B. turn off

C. turn up

D. turn down

如图所示，abcd是金属矩形框，OO′是金属导体，可沿框无摩擦地滑动，整个框放在与框平面垂直的匀强磁场中，磁感应强度为B，OO′长为L，电阻为R，ab、cd电阻均为2R，ad、bc的电阻忽略不计，当OO′向右以速度v匀速滑动时，作用在OO′上的外力大小为________，滑动过程中，金属导体OO′两端的电压大小是________。

新生儿产前失血的主要病因是（）。

A.脐带畸形

B.经胎盘失血

C.脐部出血

D.胃肠道出血

E.内出血

Which of the following statements is the most appropriate title for the passage

Which of the following statements is NOT true of "free flight"

A．Commercial aircraft is guided by GPS.
B．Civilian aircraft are free to move over all territories.
C．Cargo carders no longer collide with one another.
D．Passenger flights are safe to fly with military aircrafts.

抵押物因附合、混合或者加工，抵押权应当如何认定？