下列有关食用油安全的说法完全正确的是？（）A、食用一级、二级油，这种油烟点低 B、最好

阅读理解。

     Lucy shows the weights of her classmates. She draws a chart to show the different weights in her

class.

1.What is the weight of most of the students?   

A.55kg.    

B.50kg.      

C.10kg.

2. How many students only weigh 30 kg?                      

A. Three students.            

B. Thirty students.              

C. We can't get the answer.

3. How many students weigh 80 kg?                  

A. One.                        

B. None.                        

C. We don't know.

4.Which of the following is not true?                  

A.4 students weigh 40 kg.                

B. Only one student weighs 70 kg.

C. Most students weigh 55 kg.

5. How many girl students are there in Lucy's class?         

A.38.                  

B.40.                  

C.We don't know.

如图所示，与水平面夹角为30°的固定斜面上有一质量m=1.0kg的物体。细绳的一端与物体相 连，另一端经摩擦不计的定滑轮与固定的弹簧秤相连。物体静止在斜面上，弹簧秤的示数为 4.9N。关于物体受力的判断（取g=9.8m/s²），下列说法正确的是

A．斜面对物体的支持力大小为4.9N，方向垂直斜面向上

B．斜面对物体的摩擦力大小为4.9N,方向沿斜面向上

C．斜面对物体的支持力大小为，方向竖直向上

D．斜面对物体的摩擦力大小为零

肾损伤非手术治疗卧床的时间为

A．8d

B．10d

C．12d

D．14d

E．血尿转清后即可起床

在加密技术中，作为算法输入的原始信息称为

A．明文

B．密文

C．报文

D．暗文

汽缸干燥过程注意事项有哪此？