When you're willing to ask for what you want but don't insist on getting it, there are some potential hidden benefits as well. For example, you sometimes 1 the sympathy and generosity in others.

    Several years ago, I arrived in Mumbai very late one evening. 2 having a confirmed reservation, the hotel was overbooked and was 3 people away. The man in front of me was angry and became very 4.

    He insisted on getting his way---but there were no 5. He stormed out, defeated and angry. He was totally 6 to the fact that it wasn't the receptionist's 7. It wasn't personal.

    I walked up to the receptionist and said8, “I really understand your9 and don't blame you a bit. I would 10 it so much if you would help me. I know you don't have any rooms here, but could you help me find another 11 close by?” I thought it was wise to ask---as long as I didn't 12.

    Hearing my words, she was 13. Remarkably, she said she had some great news, She had completely 14 that fact that one of the guests had to leave in an 15 and wouldn't be back. It turned out the most expensive room! Because I had been so 16, she gave it to me at lower rate.

    The question is, why didn't she 17 this empty room and give it to the angry man in front of me? I think the answer is pretty 18. His insistence pushed her away and may have even 19 to her “forgetfulness”. When I was talking to her, however, she relaxed and felt less 20. Her memory returned and I ended up getting a few hours of much-needed sleep.

    So be sure to ask for what you want, but don't insist on getting it.

a、加热氯酸钾晶体和二氧化锰粉末；

b、加热高锰酸钾固体；

c、用二氧化锰粉末作催化剂使过氧化氢（H₂O₂）溶液分解产生水和氧气．

考古工作者从一批出土文物中发现了一枚大约如火柴盒大小的印章(但不像火柴盒那么规则，四周和上端都有浮雕)。按常理，印章多为石头的，而这枚印章清洗后从色泽上看像是金属的。为搞清楚它究竟是什么材料的，考古人员决定测出它的密度看看。现在把这个任务交给你，请你选用实验室常见的实验器材或常见的生活用品做实验。有一点需要说明的是，这枚印章放不进常见的量筒或量杯。