Many people think it is very exciting and admirable(令人羡慕的) to be an actor. The actors often wear the most beautiful and fashionable clothes and they can make a lot of money. Many people like them and they have so many fans. But in fact, the job of an actor can be very tiring and hard. To make good movies, for example, action movies, the actors need to go to some remote(偏远的) places. There they don't have good places to stay or nice food to eat. They often have to get up early and go to bed very late. When they are too busy, they don’t have time to sleep or relax. It's very hard.

一个弹簧挂60N的重物时，弹簧伸长3cm，若该弹簧挂重为100N的物体时，其长度为15cm．求：

下列物质颜色为黑色的是（   ）

近年来相继发生恶性食品安全事件折射出了社会信用制度的缺失，人们更加呼唤中国诚信传统的回归。今天在全社会增强诚信意识（   ）                                     
①体现在市场经济条件下“诚实守信”是思想道德建设的核心
②有利于加强社会主义思想道德建设
③是贯彻社会主义荣辱观和公民道德规范的要求
④必定会推动“为人民服务”这一思想道德建设的原则的发展

关于狮身人面像（右图）的传说实际上属于