玻璃电极初次使用前,必须在蒸馏水中浸泡数日,平时也应浸泡在蒸馏水中备用。
参考答案:对
句型转换。
1. The student has a cold. (改为同义句)
The student _______a_______.= The student _______a_______
2. I have a stomachache. (改为同义句)
I have an _______ _______my stomach.
I have a _______ _______my stomach.
My stomach is _______
I have a ________ stomach.
My stomach _______
从Windows环境进入MS-DOS方式后,返回Windows环境的DOS命令为 【3】 。