Bob has got good exam results. His parents are proud of his ______.
A:success
B:chance
C:idea
D:dream
读我国某省行政中心位置及其气温曲线和降水柱状图,回答问题
如果连入同一电路的电灯L1和L2两端电压相同,则它们( )
先化简,再求值: a2−b2a÷(a−2ab−b2a) ,其中 a=2+3 , b=2−3 .