我经常帮妈妈打扫卫生 I often help my mother ---- ---- ----.

我经常帮妈妈打扫卫生 I often help my mother ____ ____ ____.汤姆正在学用筷子吃饭Tom is learning to eat ____ ____.他一到这儿就来看我He came to see me ___ after he ____.在北京大学读书是很幸福的It's ____ ____ ____ in Beijing University.