题目

地球自转产生了：A．四季变化B．昼夜交替C．昼夜长短D．昼夜 答案：B解析:地球自转运动产生了昼夜交替和地方时的变化。19．What will Simon do then？A．Help the girl do the exercise． B．Ask Daniel for help．C．Ask Daniel to play with him． D．Ask Daniel to talk to him．