题目

阅读理解Hello, everyone! Thank you for joining Around China show. Today, we're in Dalian. It's really a beautiful city. I like it very much. The people here are very friendly. The weather here is sunny and warm. There are lots of people on vacation here. Now we're on the beach(海滩). Some are taking photos and some are swimming. Some young people are playing volleyball. They are having a good time. Look! There is a girl by the sea. She's drawing there. Many people are watching her. There are also two musicians by the sea. One is playing the guitar and the other is singing. They look so c有一台四缸发动机，其主要技术指标有：排量2.0L、输出功率120kW、转速6000r/min．其中排量等于四个汽缸工作容积的总和，汽缸工作容积指活塞从上止点到下止点所扫过的容积，又称单缸排量．它取决于活塞的面积和活塞上下运动的距离（即冲程长）．转速表示每分钟曲轴或飞轮所转的周数．则：①该发动机在1s内做功________J，1s内共有________个做功冲程，单缸排量V=________L；②在每个做功冲程里，发动机做功W=________J．