— I haven't got the reference book yet, but I'll have a test on the subject next month.
— Don't worry. You _______ have it by Friday.
在“草→食草昆虫→青蛙→蛇→鹰”食物链中,个体数量最少的动物应该是( )
下列陆地生活的动物中,不能用气管或肺作为呼吸器官来呼吸的是( )