物质受到射线的作用激发，退激后可放出（）。 A.γ射线 B.特征X射线 C.荧光 D

绒毛膜癌主要播散的方式（）

A．淋巴转移和种植 

B．血行转移和淋巴转移 

C．直接蔓延和种植 

D．直接蔓延和淋巴转移 

E．血行转移

阅读理解。

     This is the twin's(双胞胎的) room. It's a nice room. The two beds are in the room. One is Lucy's and the other

(另一个) is Lily's. They look the same. Their coats are on the beds. We can't see their shoes. They are under the

beds.

     The twins have desks and chairs. Their clocks, books and pencil-boxes are on the desks. Their bags are behind

(在…后面)the chairs.

1. --- What kind(种类) of room is it?

--- It's a ________.

A. classroom

B. big room  

C. bedroom

2. Which one is right?

A. Lily's coat is on the desk.

B. Lucy's shoes are under the chair

C. Two beds are in the room.

3.---Where are their bags?

--- They are _____________.

A. on the wall    

B. behind the chair    

C. under their beds

4. Their shoes are ____________.

A. under the desks    

B. on the beds  

C. under the

5. We can see _______________.

A. their shoes under the chairs

B. their clocks and books on the desks.

C. their bags are under the beds

如图甲所示，静止在光滑水平面上的长木板B(长木板足够长）的左端放着小物块A.某时刻，A受到水平向右的外力F作用，F随时间t的变化规律如图乙所示，即F=kt，其中k为已知常数.若物体之间的滑动摩擦力 的大小等于最大静摩擦力，且A、B的质量相等，则下列图中可以定性地描述长木板B运动的v-t图象的是

2012年6月18日，我国“神州九号”和“天宫一号”首次载人交会对接成功．两飞行器形成一个稳定运动的组合体后，“神九”相对于“天宫”来说是            的。航天员与地面指挥站互相交流是利用                         传递信息的。