know black from white

例句：

1. 1. I know that he willarrive at the airport on time.
   我知道他会准时到达机场。
2. 2. She knows how to fixcars.
   她知道如何修车。
3. 3. Weneed to know more aboutthe history of the country.
   我们需要更多地了解这个国家的历史。