搜题请搜索小程序“爱下问搜题”
问题 判断题

勃氏比表面仪的校准周期确定原则是：每年至少校准一次；使用频繁时半年1次；仪器设备维修后需要重新校准。

答案

参考答案：对

计算题

如图所示，A、B是两块质量均为m的木块，它们之间的动摩擦因数为μ，B与地面间的动摩擦因数也为μ，现对A施加一个水平向右的拉力F，可使A向右，B向左都做匀速直线运动.若滑轮处的摩擦不计，则F的大小等于多少？
查看答案
填空题
阅读下面短文，根据以下提示：1）汉语提示 2）首字母提示 3）语境提示，在每个空格内填入一个
适当的英语单词，所填单词要求意义准确，拼写正确。
Dear Sir,                                                       
     I'm a senior high school student. I was caught (1)______ (作弊) in the exam and got (2)_______ (惩罚).
I know I was totally wrong and now I (3)f______ so ashamed. To my teachers, I was once an outstanding
student. I did well (4)______ my school work most of time. In (5)______, I worked hard in the student union. 
Before the exam, I had a strong (6)d______ to get a good mark to please my teachers. Now I regret (7)______
I have done, though I know the result can't be (8)______ (改变). Recently  I'm (9)t______ by the disturbing
problem. I just dare not tell my parents about it and I'm worried about my(10) ______ (将来) What should I
do?                                               
                                                                                                                                                   Jimmy  
查看答案