单杆双作用活塞缸差动连接时，活塞杆直径减小，推力（），速度（）。
参考答案：小；快
根据下面对话中的情景，从方框中选出恰当的语句填入对话中的空白处，使对话恢复完整.其中有两项是多余的.
John: Would you like to go to New York with me over the vacation, Jim?
Jim: 小题1: But where will we stay?
John: At my uncle´s. I always stay with him and there´s a room for you, too.
Jim: OK. He won´t mind?
John: Of course not. 小题2:.
Jim: Will we drive to New York?
John: Yes, it takes about six hours.
Jim: 小题3:
John: It may be cloudy and rainy. 小题4:.
Jim: Well, when will we leave?
John: 小题5:
Jim: No problem. See you then.
根据下面雌果蝇染色体示意图，填充下列空白：
常染色体是（）
