A:①②
B:②③
C:②④
D:③④
大航海时代
海洋是一个国家通向远方的重要路径。1405年,明成祖派遣郑和率船队出使西洋;1492年,哥伦布获得西班牙女王的资助踏上了开辟新航路的征途。人类大航海时代的序幕徐徐拉开……
问题:
根据句意或中英文提示写出所缺单词。1. Water covers about three quarters of the earth's ____ .(表面)2. ____ (though) he is very clever, he doesn’t work hard at his lessons.3. Are you ____ (sure) Mr Wang will come to our meeting?4. ____ with life on Earth, life on Mars will be better in many ways.(比较)5. The Great Wall is one of the ____ (unusual things that fill people with surprise) in the world.
23+19=____