“Boys and girls, you should ________ when having lectures,”asked the teacher．
A.behave yourselfB.behave yourselvesC.behave youD.behave yours在线课程B
解析：
behave oneself是词组，表示“有好的行为举止”。这句祈使句是针对Boys and girls而言的，所以oneself应为复数。