1) It is widely recognized that extensive deforestation contributed to heavy summer flooding. （众所周知）

　　2) It is reported that 800000 applicants sat for the National Master’s Entrance Test in 2003. （据报道）

　　3) It is estimated that two thirds of the cities of our country will be in acute shortage of fresh water by 2010. （据估计）

　　4) It is generally accepted that to practice euthanasia on a patient who is still alive is inhuman. （人们普遍认为）

　　5) It must be admitted that the price war will disturb the normal order of the market. (必须承认)

　　6) It cannot be denied that the overgrowth of tourism may destroy the ecological balance of some scenic resorts. （不可否认）

　　7) It is known to all that physical exercises can improve and enrich our physical and mental well-being. （众所周知）

　　8) It goes without saying that our actual knowledge of natural laws is still imperfect and limited. （毫无疑问）

　　2． It is + 形容词 + to do sth / that…

　　1) It is obvious /evident /clear /apparent that the situation is caused directly by excessive commercial fishing. （很显然）

　　2) It is understandable (inevitable) that people’s attitudes are divergent on this controversial issue. （可以理解/不可避免的是）

　　3) It is unimaginable (incredible/unbelievable) that such a boy of 17 should have had three novels published. （难以置信的是）

　　4) It is imperative that something urgent be done to combat the widespread use of illegal drugs among teenagers. （…是很有必要的）

　　5) It is upsetting to find people who behave differently from us. We may, at first, assume that something is wrong with them. （…是令人恼火的）

　　6) It is impossible to concentrate if you are tense or nervous.（…是不可能的）

　　7) It is highly necessary for our government to stop the corruption of government officials.（某人很有必要做某事）