题目

请仔细阅读第56—60题中碰到陌生人或得到旅行机会的说明，从A—F中选出符合要求的最佳选项，其中一项为多余选项。 A. Exchange houses            B. Send some photosC. Be friendly to the locals      D. Give Chinese presentsE. Take a photo album with you  F. Share something special about China  56. Be polite and friendly. Remember to put yourself in social situations. Restaurants, shops and parks are all great places to meet people. If you want to make local friends in a country, stay near the places the locals often visit. 57. Ke现有0.27kg质量分数为10%CuCl2溶液，测得其密度为1.08g/cm3．试计算：（1）溶液中氯化铜的物质的量；（2）溶液中氯离子的物质的量浓度；（3）为使这些铜离子完全沉淀，需要加入1mol/L的NaOH溶液的体积是多少？