在一根电阻丝两端加上一定的电压U,电功率为P,则导线的电阻值为____,若将导线均匀拉长为原来的3倍,则电阻值变为原来的____倍.
Tom said they ____ come back the next morning.
图为某温室大棚内一天中二氧化碳含量的变化曲线,据此曲线分析正确的是( )
The population of China is __________ than that of _________ country in the world