根据拼音写出相应的词语。
兔笼里有10只白兔,跑出一只,一定是白兔.
人口自然增长率的大小取决于( )
牙齿对动物的生存和生活具有重要意义,如图是某动物上、下颌骨及牙齿的示意图,请据图回答下列与牙齿有关的问题.
——I hear you______ in a sports center. What's it like?——Well, it's very hard work and I'm always tired, but I don't mind.