单选题 9.  Not until this week were they aware of the problems with the air-conditioning units in the hotel rooms.
【正确答案】 C
【答案解析】 翻译这句话的关键在于弄清句子结构,并认清几个重点词汇的意思。这是一个倒装句,not until一般翻译成“直到……才……”,be aware of意为“意识到”,problems with意为“……有问题”,故最佳答案应该是C。