1)It is+形容词+thatIt is conceivable that knowledge plays an important role in our life.可想而知，知识在我们的一生中扮演着一个重要的角色。2)It is+形容词+to do/ doingShe had said what it was necessary to say.她已经说了一切有必要说的话。3)祈使句/名词+and/ orWork hard, and you will finally be able to reach your destination.努力工作，你就能实现自己的目标。4)as+many/ much+名词+asIt is said that visitors spend only half as much money in a day in Leeds as in Lon-don.据说，游客每天在利兹的花销仅为在伦敦的一半。5)倍数词+as+形容词+asThe reservo
