现有4.6g某有机物在空气中完全燃烧,生成了8.8gCO2和5.4g水,该有机物可能是[ ]
A.CH4
B.C2H4
C.C2H6
D.C2H5OH
答案:B
句型转换 (每空1分,共10分)
小题1:There are some vegetables for dinner. (改为否定句)
There _______ ________ vegetables for dinner.
小题2:How’s the weather in Beijing. (同义句转换)
_________ the weather ________ in Beijing.
小题3:The students are having an English class . (对画线部分提问)
_________ are the students ____________?
小题4:Your brother has a great time playing computer games. (同义句转换)
Your brother has ________ _________ computer games.
小题5: No photos here. (同义句)
_____________ ____________ any photos here.
“电介质偶极子内的正负电荷随着电流正负半周的高速变化,也不断反复取向而产生180°的旋转,偶极子内束缚电荷位置移动”产生()
A.涡电流
B.位移电流
C.介质损耗
D.欧姆损耗
E.非热效应