【简答题】It is very important to have healthy teeth. Good teeth help us to chew our food .They also help us to look nice. How does a tooth go bad? The __51 begins in a little crack in the enamel(珐琅) covering ...
【单选题】We had a very bad journey, the food served on the flight was terrible, ________, we failed to claim our luggage on arrival, they informed us that our luggage had been uploaded on another flight. Can y...