如 important 重要的, necessary 必须的, natural 自然的, easy 容易的, safe 安全的, common 普遍的,
normal 正常的, hard 困难的, difficult 困难的, dangerous 危险的, unusual 不寻常的,possible 可能的，等等。
例：It is very important for us to study english well.
2. It is +形容词+(of sb.) to do sth. 句型
该句型与上面的相似，这里的形容词是表示不定式逻辑主语人物的品质或特征的词，所以用of sb., 不用for sb. 常见的这类形容词有： lazy懒惰的,good好的, bad, brave勇敢的, careless粗心的, clever聪明的, friendly友好的 foolish愚蠢的, honest 诚实的, kind 善良的, polite 礼貌的, rude 粗鲁的, silly 愚蠢的,wise 睿智的, 等。例：It is very kind of you to help me with my English.帮助我学习英语，你真的太善良了.例：It's impolite of you to say so.那样说是不礼貌的。3. It is +名词或名词短语(a pity, a shame, a fact, a wonder, a pleasure,good idea ,my duty...) +that 从句例：It's a good idea to play basketball after class.下课后打篮球是一个好主意例：It is a pity that he can't come to my party.他没能来参加我的派对，真遗憾！
