搜题请搜索小程序“爱下问搜题”
问题 单项选择题

称取硅酸盐试样1.0000g，在105℃下干燥至恒重，又称其质量为0.9793g，则该硅酸盐中湿存水分质量分数为( )。

A．97.93%

B．96.07%

C．3.93%

D．2.07%

答案

参考答案：D

选择题

一列简谐横波沿直线水平向右传播，先后通过介质中的P、Q两质点。波速为="80" m/s，频率为="100" Hz，、Q两质点的平衡位置相距="6.6" m。若以Q质点开始振动的时刻作为计时的零点，Q质点的振动图像如图a所示。则质点的振动图像是图b中的

查看答案
完形填空

阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空格处填入一个适当的词或使用括号中词语的正确形式填空。

Nowadays, millions  小题1:  lonely singles are now going online instead. 小题2:_   World Wide Web is quickly becoming the world’s most popular matchmaker ( 媒人 ).

Singles are flocking (涌向) to the Internet  _小题3:__  ( largeness ) because their busy lifestyles leave them little time to look for a significant other. Using dating sites (约会网址) is quick and convenient. Many singles say the regular dating scene 小题4: ( just lead ) them from one bad experience to __小题5:_  and are ready to try something else. Dating sites also make 小题6: easy to avoid someone  _小题7:_  you are not interested in. In the real world,   _小题8:  , ignoring someone you don’t like can be difficult.

Despite all the advantages, online dating also presents its own set of problems. People aren’t always those who they declare to be in their online  __小题9:__ ( describe ). Safety is another concern. You are just  __小题10:  ( like ) to find a criminal online as you are Mr. or Miss Right.
查看答案