是by plane or by train還是by plane or train　　

有網友問，英語該說by plane or by train還是by plane or train？其實，兩者都可以。當對by plane（乘飛機）、by train（乘火車）、by bus（乘公共汽車）等方式狀語進行選擇時，既可以在or后面重復介詞by，也可以省略by。若用by plane or by train，說明是在by plane和by train中選擇；若用by plane or train，則說明是有plane和train中選擇。類似地如：　　

Are you going by sea or by air? 你打算坐船去還是坐飛機去? 　　

Do you hope to freight your belongings by air or sea? 你是想把東西空運去還是海運去? 　　

以下句子也屬類似情況：　　

Did you contact her by email or fax? 你是用電子郵件還是用傳真與她聯系？　　

Had it happened by accident or by design? 那是偶然發生的還是人為讓它發生的。　　

Do you think the house was burnt down by accident or design? 你認為房子是意外燒毀的還是有人故意放火的？　　

但是，如果兩個短語所用的介詞不一樣，則不可省略。如：　　

Will you pay in cash or by credit card? 您是付現金還是刷卡？　　

Did he do so on purpose or by chance? 他這樣做是有意的還是無意的?　　

Did he do it by accident or on purpose? 他做這事是偶然的，還是故意的?