题目

下列各组物质的水溶液，只用组内两两物质间的反应，不用其他试剂，不能将其一一区别的是（ ） A．NaCl、Na2CO3、Ca（NO3）2、HCl        B．Na2SO4、BaCl2、K2CO3、KNO3 C．FeCl3、NaOH、H2SO4、Ba（OH）2        D．K2CO3、H2SO4、KNO3、BaCl2 答案：分析：A、碳酸钠与盐酸混合能产生气泡，剩余的两种物质为氯化钠和硝酸钙，将产生气泡的两种物质中任取一种，与另外两种溶液混合，若能产生白色沉淀，则取的是碳酸钠，剩余的是盐酸，与之产生沉淀的是硝酸钙，剩余的是氯化钠，故A正确； B、氯化钡与硫酸钠和碳酸钾混合能产生白色沉淀，产生18、Do you know Mother' s Day? It is a holiday for mothers. It was celebrated first in the United States, England, India and some other countries. In a short time, it became widely celebrated. Mother' s Day falls on the second Sunday in May. On that day, many people send gifts(礼物) of love to their mothers. Those whose mothers are still living often wear a pink or red rose, while those whose mothers are dead wear a white one. The idea of a day for mothers' was first given by Miss Anna Jarvis of Philadel?phia. Because of her hard work, the celebration of the first Ameircan Mother' s Day was once held in Philadelphia on May 10, 1908. Soon the holiday became pop?ular all over the country and around the world. In China, people do the same on the day for mothers. And， in some cities, people sometimes ask a song to be broadcast(广播) for his or her mother only. This might cost a little money for some of them, but, as it says, "Love is invaluable. ” 1. Mother's Day________. A.  is celebrated in the United States only B. is a holiday for mothers C. falls on May 10 every year D. is not popular around the world 2. What day is Mother's Day every year? A. The first Sunday in May.         B. The second Sunday in May. C. The third Sunday in May.        D. The fourth Sunday in May. 3. Why do people send gifts to their mothers on Mother's Day? A. Because their mothers need gifts. B. Because their mothers are free on that day. C. Because they want to show their love for their mothers. D. Because it is the best way to celebrate Mother's Day. 4. Who celebrated the first Mother's Day? A. The people all over China. B. The people around the world. C. The people in India and Japan. D. Some American people. 5. The underlined word "invaluable" means A．无价的    B．万能的    C．可有可无的。    D．有价的