摘要：
DescriptionLamps-O-Matic company assembles very large chandeliers. A chandelier consists of multiple levels. On the first level crystal pendants are a... 阅读全文
摘要：
DescriptionThere is a famous joke-riddle for children:Three turtles are crawling along a road. One turtle says: "There are two turtles ahead of me." The other turtle says: "There are two turtles behind me." The third turtle says: "There are two turtles ahead of me and two tu 阅读全文