当起吊载荷达到额定重量的90%以上时，应先将重物吊离地面200-500mm后，重点检

A．延长

B．提前

C．减少

D．推迟

短文改错

     As student of your age, I understand your situation. That you are facing is common

among teenagers. However, it should be wise not to do anything may hurt her feelings.

Here are a few suggestion. First, it's advisable to talk most with your mom. Heart to

heart talks helped you understand each other better. There are also opportunities to let

her knowing your ideas and attitudes toward many things. Second, you should learn to

do our own things well, proving to your mom that you are already a "grownup". It's even

the better whether you share more in the housework, such as cleaning, washing and cooking.

_______________________________________________________________________

一根长方体木料的横截面面积是1.2平方米，长15分米，它的体积是______立方米．

（4分）如图所示，是一个学生课后做的“用广口瓶和直尺测定水

的折射率”小实验．请填写下述实验步骤中的空白．①用直尺测  

出广口瓶瓶口内径d；②在瓶内装满水；③将直尺沿瓶口边缘   

    插入水中；④沿广口瓶边缘向水中直尺正面看去，若恰

能看到直尺的零刻度（即图中A点），同时看到水面上B点刻度的

像恰与A点的像相重合；⑤若水面恰与直尺的C点相平，读出

    和   的长度；⑥由题中所给条件，可以计算水的折射

率为              ．

运方脱班，站方可按核定车辆座位运费总额的（）向运方收取脱班损失费。

A、200％

B、150％

C、100％

D、50％