已知,AC∥ED,∠C=26°,∠CBE=37°,则∠BED的度数是( )
A:53°
B:63°
C:73°
D:83°
如图是元素x的原子结构示意圈.下列说法正确的是
已知a+2ii=b+ia,b∈R,其中i为虚数单位,则a+b=( )
— Mary, how did your Math test go?
— I had thought I ________, but in fact I came in the top 10 in my class.
下列物质中,属于纯净物的是()