有下列情况之一的，不得从事接尘作业？

阅读理解。

     Hi! My name is Tina. I'm an English girl. I like sports and my favorite (最喜爱的) one is basketball.

 My favorite basketball star is a Chinese boy. His name is Yao Ming. Do you know him? I have some

 great photos of him. They are on the wall in my room.

     In my room, I have a small sports collection. Look! Three soccer balls are on the desk. Five baseballs 

 are under the chair. On the table are three basketballs. Many ping-pong balls are in my drawer. Do you

  like my collections?

1. Tina likes playing ______ best (最) of all.

    A. basketball

    B. soccer

    C. ping-pong

2. Does Tina have photos of a sports star? ______.

    A. Yes, she does          

    B. No, she doesn't

    C. Yes, but only one

3. Three soccer balls are ______.

    A. under the chair

    B. on the table

    C. on the desk

4. She has ______ in the drawer.

    A. 5 baseballs

    B. 3 basketballs

    C. many ping-pong balls

5. Which sentence is TRUE(正确)?

    A. Tina's favorite basketball star is a girl.

    B. Some photos are on the wall in Tina's room.

    C. Tina has many tennis balls in her room.

函数y=2^-x的值域是（　　）

A．R

B．（-∞，0）

C．（-∞，1）

D．（0，+∞）

胎儿胎盘循环建立是在受精后

A．第一周

B．第二周

C．第三周

D．第四周

E．第五周

小企业发展不足，是我国目前中等收入水平人口少、经济内生动力不足的主要原因。根据我国当前实际，推动小企业发展的关键是[ ]

A．促进中小企业所有制改革

B．以公有制为主体，多种所有制经济并驾齐驱

C．鼓励、支持、引导小企业的发展，放宽市场准人

D．保证小企业在国民经济中地位平等，促进企业公平竞争

负重奔跑是体能训练常用方式之一，如图（3）所示的装置是运动员负重奔跑的跑步机。已知运动员质量为m₁，绳拴在腰间沿水平方向跨过滑轮（不计滑轮摩擦、质量）悬挂质量为m₂的重物，人用力向后蹬使传送带沿顺时针方向转动，下面说法正确的是

A．若m₂静止不动，运动员对传送带的摩擦力大小为m₂g

B．若m₂匀速上升时，m₁越大，传送带对运动员的摩擦力也越大

C．若m₂匀减速上升时，m₁越大，传送带对运动员的摩擦力也越大

D．人对传送带做功的功率与m₂的运动状态无关