摘要： Your Ride Is HereIt is a well-known fact that behind every good comet is a UFO. These UFOs often come to collect loyal supporters from here on Earth. Unfortunately, they only have room to pick up one ... 阅读全文

摘要： Friday the ThirteenthIs Friday the 13th really an unusual event? That is, does the 13th of the month land on a Friday less often than on any other day of the week? To answer this question, write a pro... 阅读全文