The Wavle is a small river that cuts across the park near my home.
主语是The Wavle,谓语是系动词is,表语是river,that cuts across the park near my home是river的定语,在句子中做表语补足语；
some people on the bank called out to the man in the boat.
主语是some people,on the bank做主语的定语；谓语是called out to;宾语是the man,in the boat做宾语的定语；
the ball sturk him so hard that he nearly fell into the water.
主语是the ball,谓语是sturk；宾语是him,so hard that he nearly fell into the water做状语从句；
the man laughed when he realized what had happened.
主语是the man,谓语是laughed,when he realized what had happened做时间状语从句.