【单选题】At the bottom of the world lies a mighty continent still wrapped in the Ice Age and, until recent times, unknown to man. It is a great land mass crisscrossed by mountain(51) whose extent and elevation...
【简答题】Give this memory test a try. Mix up 52 playing cards. Now look at the top seven for a second. Can you remember them in order? Players at the World Memory Championships can. In fact, the 2002 champion ...
【单选题】阅读材料,回答题。 Man cannot go on increasing his number at the present rate. In the next 30 years man will faca period of crisis. Some experts believe that there will be a widespread food___ 51 ____. Other e...