单选题 You'd better write down her number and address ______ you should need them.
A. unless B. in case C. on condition that D. if only

【正确答案】 C

【答案解析】[解析] A项与not连用；B项意为“一旦”；C项意为“倘若”；D项意为“要是……有多好啊”。故本题答案为C。