4．... (不可能预算出) what price it would fetch if it ever came on the market.

5．When you have made the face, you can take a photo of it, (目的是) you can keep your unusual picture forever.

　　【答案】　1.in case　2.As you know　3.this is the most valuable painting　4.it is impossible to calculate　5.so that

　　Ⅳ.回顾话题

　　用本单元的词汇或句式完成写作任务

　　一个新的俱乐部在上周成立了。为了加强宣传和积累更多资金，这个俱乐部组织了一次去南方一个城市的旅行。加入俱乐部的成员在正常价位上折扣30%后只需交300美元。昨天我们出发去旅行了。听说那儿风景优美，但天气多变。此外我们已提前打电话预定了住处。祝愿我们的这次旅行一切顺利。

　　【参考范文】　

　　A new club was set up last week.To strengthen publicity and build up more fund，the club organized a travel to a city in the south.The members admitted to the club only needed to pay $300 after receiving a 30% discount below the normal price.Yesterday all of us set out to travel.I heard that the scenery there was beautiful but the weather was changeable.In addition，we have booked accommodations by telephone in advance.Wish everything of our trip would go well.