A:obviously; told the truth
B:obvious; told a truth
C:obvious; told the truth
D:obviously; told truth
John is ______ a birthday party in his house with his good friends. ( )
①将称好的氯化钠固体转移到烧杯中时,有少量溢出;
②用量筒量取水时,将量筒举过头顶读数;
③溶解过程中未用玻璃棒搅拌;
④盛装生理盐水的试管刷洗后未干燥.
已知3xa+bya-b与2xa+1y是同类项,那么 ( )