discovered为什么呢？还有一题the poor dog had no food at that time.(保持原意)the poor dog had ______ _______ eat at that time哥伦布发现美洲新大陆发现=discoverthe poor dog had __nothing ____ ___to____ eat at that time再问两题给加分！！what does expo mean？（保持愿意）_____ the ______ of expo.i prefer the red ballpoint pen.(同上)i_____ the red ballpoint pen_____What's ......meaning.....like.......best