人们在日常生活中使用的温度计,是根据液体____的规律来测量温度的.某地蛇年的大年初一分别放在室内和室外的二支温度计,它们的示数如图甲、乙所示,其中图是室外的温度计____,其示数是____℃.
More and more children in the countryside are ________ school at an early age to look for work in the cities.
实验室制取氢气的步骤,正确的顺序是( )
①检查装置的气密性 ②加入稀硫酸 ③加入锌粒 ④收集氢气