宝宝学走路时经常跌坐在地上。

Babies often fall on their ___bums when learning to walk.

宝宝刚学会走路时经常摔跤，所以他裤子后面有个保护小屁股的垫子。

The baby often falls when learning to walk, so there's a cushion to protect his ___bottom on his pants.

别整天躺在沙发上当个懒汉，找点事情做吧！

Stop being a ___bum on the couch all day and find something to do!

他经常在酒吧里蹭别人的酒喝。

He's always ___bumming drinks at the bar.