I an old letter while I was searching my drawer.A. came upB. came acrossC. came onD. came

问题补充：

I an old letter while I was searching my drawer.

A. came up

B. came across

C. came on

D. came about

答案：

A. came up

(答案→)B. came across

C. came on

D. came about

解析：动词短语辨析。A走近；发生；出现；B遇见；发现；C加油；过来；D形成，产生，发生；句意：当我们在搜查抽屉的时候，我发现了一封以前的信。根据句意说明B正确。