I’ll let you have the book on condition that you return it to me next week. 我可以把书借给你,条件是你下星期得还给我。 Take an umbrella with you in case there is rain this afternoon. 随身带着把伞,以防今天下午下雨。 [温馨提示] (1)在条件状语从句中,用一般现在时代替一般将来时,一般过去时代替过去将来时。 If he arrives tomorrow,I will be waiting for him at the airport. 如果他明天到,我将在机场等他。