坐标原点）的最大值为2，则m=____．

长方体有6个面，每个面都一定是正方形．

读中国地形图填写地形名称

盆地：1____、2____；

高原：3____、4____；

山脉：5____、6____、7____、8____、9____；

平原：10____．

在尿液形成过程中，肾小球和肾小囊内壁起____作用，肾小管起____作用．

Different countries have different customs. When you travel to another countries，please follow their customs，just as the saying goes，“             .”Very often people who travel to the United States forget to tip（付小费）.It is usual to tip porters who help carry your bags，taxi drivers and waiters. Waiters expect to get a 15% tip on the cost of your meal. Taxi drivers expect about the same amount.
In England，make sure to stand in line even if there are only two of you. It's important to respect lines there. It’s a good idea to talk about the weather. It's a favorite subject of conversation with the British.
   In Spain，it's a good idea to have a light meal in the afternoon if someone invites you for dinner. People have dinner very late，and restaurants do not generally open until after 9 pm.
   In Arab countries，men kiss one another on the cheek（脸颊）. Your host may welcome you with a kiss on both cheeks. It is polite for you to do the same.
   In Japan，people usually give personal or business cards to each other when they meet for the first time. When a person gives you a card，don't put it into your pocket right away. The person expects you to read it.Don't forget to be careful of your body language to express something In conversation. A kind of body language that is acceptable in one culture may be impolite in another.