He swam across the river last year.为什么用across

He swam across the river last year.为什么用across the man swam (across/through) the changjiang river last year at last he s() in swimming across the river you can see the river across which the boy swam Did you swim across the river Have you swam across the river The swimmers all swam across Changjiang River （）.（success） He is swimming across the river.用across the river提问英语句子 We swam across the river这里ACROSS充当的是介词? he is swimming across the river改错 I can swim across the river.为什么用across而不是cross? march across the park为什么用across? The dog swam ___ the river.A.cross B.on C.through D.across