英語句型學(xué)口語097

97. only if...
決不······除非······
用法透視
only if 意思是"只有......才......"。only if即可并列在一起，也可分開。
支持范例
1. A student is allowed to enter this room only if a teacher has given permission.
只有得到教師的許可學(xué)生才可以進(jìn)入這個(gè)房間。
2. Seat belts are effective only if they are correctly adjusted.
座椅安全帶只有調(diào)節(jié)好才能起作用。
3. We can only reach agreement if we both put our cards on the table.
我們雙方只有開誠布公來談才能達(dá)成協(xié)議。
會(huì)話記憶
A: My shirt needs ironing. Could you please help me with that, Mary?
我的襯衫需要熨一下。你能幫個(gè)忙嗎，瑪麗？
B: No way. Do it yourself.
不行。你自己干吧。
A: Please, I promise this is the last time.
求求你啦，我保證這是最后一次。
B: OK, I'll iron your shirt for you, but only if you make me a cup of coffee.
好吧，我來為你熨襯衫，但條件是你給我煮一杯咖啡。