Mrs. Green doesn't like sports. She has much work to do at home. Her mother is coming this afternoon and she goes to meet her. Near the school she looks at her watch. She has some time. So she goes into the school. Her son isn't in the classroom. She asks a boy and knows they're behind the school. She sees some boys playing there. Her son is there too. She watches them playing and soon she's angry. She takes her son to the wall. “Go home with me, Richard.” She says, "Don't play with them. I can buy a nice ball for you. Then you don't need to scramble for the ball."

如右图所示，要使灯泡L₁和L₂组成并联电路，应 （  ）

小明用凸透镜先后两次观察书本上的字，看到如图所示两种情景。以下说法中正确的是(   )

1918年7月，苏维埃人民委员会根据列宁的提议，拟定了《俄国吸收外国资本的条件提纲》，10月又通过了向农民征收实物税的法令。这些举措表明苏俄（    ）