()的功能是向无人机各用电系统或设备提供满足预定设计要求的电能。
A.配电系统
B.电源
C.供电系统
参考答案:C
— What a hot day!
— The weather report says it will be even tomorrow. [ ]
A.cooler
B.hotter
C.wetter
D.colder
某种电热暖手宝中装有质量为0.5kg的水,通电后水的温度从10℃升高到70℃。水吸收的热量是 J。[水的比热容为4.2×103J/(kg·℃)]