分类：教育/科学-升学入学-高考
问题：1.BythetimeyouarriveinLondon,we_? 
1.By the time you arrive in London,we____in Euro for two weeks.A shall stay          B have stayed     C  will have stayed   D have been staying答案是Ｃ　Ｄ为什么不行？2.We are taught that a business letter should be written in a formal style______in a personal one.A rather th1.By the time you arrive in London,we____in Euro for two weeks.A shall stay          B have stayed     C  will have stayed   D have been staying答案是Ｃ　Ｄ为什么不行？2.We are taught that a business letter should be written in a formal style______in a personal one.A rather than    B other than    C better than   D less than 答案是Ａ　　Ｃ为什么不行？
回答：1.By+将来时间状语,主句用将来时
  By+过去时间状语,主句用完成时
2.rather than 意思为“而不是”是对“in a personal one”的否定，即"a business letter"只能用formal style而不能用personal style
若选C与外国人习惯不符