李师傅在某外资企业工作，3月底拿到了4000元的工资款。这“4000元”

某租赁公司拥有汽车100辆.当每辆车的月租金为 $3000$ 元时，可全部租出.当每辆车的月租金每增加50元时，未租出的车将会增加一辆.租出的车每辆每月需要维护费150元，未租出的车每辆每月需要维护费50元.若使租赁公司的月收益最大，每辆车的月租金应该定为____．

儿童、青少年以及伤病员要多吃一些奶、蛋、鱼、肉，是因为这些食物中含有丰富的：（    ）

阅读理解。
A
    How do you go to school?  
   Sally： My school is not far from my home. It is about three kilometers. I usually walk to school, but sometimes I go to school by bike.
   Nick： My mother usually drives me to school. But when Aunt Lucy is here, I walk with her. It takes me 7 minutes by car or 25 minutes on foot.
   Mary：I go to school on the school bus. The bus comes at 8: 35 am and I get to school at 8: 50 am. I love to take the school bus because my best friend Linda takes it with me. We have lots of fun.

在Rt△ABC中，∠C=90，AC=4cm，BC=3cm，则以2.4cm为半径的⊙C与直线AB的关系是____ ．