一个四棱锥和一个三棱锥恰好可以拼接成一个三棱柱.这个四棱锥的底面为正方形,且底面边长与各侧棱长相等,这个三棱锥的底面边长与各侧棱长也都相等.设四棱锥、三棱锥、三棱柱的高分别为,,,则( )
_____ world’s largest retailer, Wal-Mart, has opened its ______ third store in Beijing, which means the firm now has 52 stores in China.
The doctor came out and said the operation was well finished. The parents smiled ________ and the nervousness disappeared from their faces.
Rainforests _______ and burned at such a speed that they will disappear from the earth in the near future.
Smile is recognized as a/an _________ language, which can be understood by people all over the world.
The conference has been held to discuss the effects of tourism _______ the wildlife in the area.