当采用加肋片的方法增强传热时，将肋片加在（）会最有效。
A.换热系数较大一侧
B.热流体一侧
C.换热系数较小一侧
D.冷流体一侧
参考答案：C
As high school students, it’s very important to keep ourselves ______ of what’s happening home and abroad every day.
A．to inform
B．informing
C．informed
D．be informed
高纬度地区森林分布较广的大洲是( )
①.南美洲 ②.非洲
③.亚洲 ④.北美洲
A．①②
B．②③
C．③④
D．①④
