Whereareyougoinginthewintervacation？Doyouwanttotraveltoothercountries？Maybeyoudon'thaveenoughmoney．NowwithGoogleEarth，youcan"fly"tomanycountriesforsightseeingwithnomoney．GoogleEarthisafreeprogram

　　Where are you going in the winter vacation？Do you want to travel to other countries？Maybe you don't have enough money．Now with Google Earth，you can"fly"to many countries for sightseeing with no money．

　　Google Earth is a free program from Google，a search engine company（搜索引擎公司） in the USA．It has photos of places around the world．These photos are taken from planes or satellites（卫星）．With these photos，people can"fly"over the earth and look down on any place they like．

　　The photos are clear．You can see buildings，roads，trees and even cars．People can even find their houses on Google Earth．Google Earth also tells some information about the places．For example，if you"fly"to Berlin，the capital city of Germany，you will see lots of small marks in the photo．They are hotels，restaurants，parks and rivers．If you click on（点击） a hotel mark，you can find its telephone number．

　　阅读短文，回答下列问题．

　　21．What is the name of this free program？___

　　22 Where are the photos taken from？___

　　23．Are these photos clear enough for people to find their houses？___

　　24．What are the small marks in the photo of Berlin？___

　　25．What information can you get if you click on a hotel mark？．___．