25. The train leaves at 6:00 p.m., so I have to be at the station ____ 5:40 p.m. at the least.
This is the largest clock in the world, _____ the minute hand is six meters long.
Sarah hopes to become a friend of _____ shares her interests.
Liu Xiang is ________ Yao Ming.
When and where to go for the on-salary holiday _____ yet.
The water will be polluted unless some measures _____.