A:Cu
B:NaOH溶液
C:熔融Na2CO3
D:乙醇
I hate people _______ laugh at others when they are in trouble.
如图,四边形ABCD与四边形A′B′C′D′全等,则∠A′=____ ,∠A=____ ,B′C′=____ ,AD=____ .
下列各有机物中,属于烃的是( )