题目

有V、W、X、Y、Z 五种元素，它们的核电荷数依次增大，且都小于20，其中X、Z 是金属元素；V和Z元素原子的最外层都只有一个电子；W和Y元素原子的最外层电子数相同，且W元素原子L层电子数是K层电子数的3倍；X元素原子的最外层电子数是Y元素原子最外层电子数的一半。由此推知（填元素符号），V       ，W        ，X     ，Y      ，Z      。由这些元素组成的一种结晶水合物的化学式为       ， 俗称           。Events     Long March exhibit     The Shanghai History Museum is putting on exhibition to remember the Long March(长征) which took place 75 years ago. More than 220 photos and 40 other things are on show. All the exhibition is explained in Chinese. The show will end on November 20.     Time: 10:00 a.m.—4:00 p.m.     Address: 1286 Hongqiao Road     Ticket: 8 yuan for Chinese / 15 yuan for foreigners     Thai elephants     Eight elephants from Thailand are an attraction for visitors at Changfeng Park by riding bikes, playing basketball, dancing and blowing a musical instrument. The elephants give three shows a day at 9:30 a.m., 3:30 p.m. and 8:00 p.m. and there is an extra show at 1:30 p.m. at weekends. The show will end on November 15.     Address: 189 Daduhe Road     Ticket: 30—40 yuan     Dancing dolphins     Dolphins jumping from the water to touch a ball, dancing to music, kissing people and doing easy math problems, and seals and sea lions, also performing, have made a large part of the aquarium in Peace Park, which interests children greatly.     Hours: 10:30 a.m., 4:00 p.m., and 7:30 p.m.     Ticket: 20 yuan for adults and 10 yuan for children     46. Where can one see the Long March exhibition?     A. In Shanghai History Museum.  B. In Changfeng Park.     C. In Peace Park.               D. On 189 Dahude Road.     47. What may interest children very much in Peace Park?     A. Elephants playing basketball.   B. Dolphins dancing to the music.     C. Seals riding bikes.             D. Sea lions blowing instruments     48. How much should a child pay to go into Peace Park?     A. Five yuan.  B. Fifteen yuan.   C. Ten yuan.       D. Twenty yuan.     49. Which of the following is true?     A. The Long March exhibition is explained in English.     B. The sea animals can work out difficult math problems.     C. Thai elephants’ shows can only be seen in the day.     D. The sea animals perform three times a day.