1) there is no point in doing sth.
　　该句型意为“做…是无济于事的／没有什么用的”。可以用very little 或not much等来代替no。其中的point是不可数名词，作“目的”、“用处”解。
　　There is very little point in arguing with him.
　　2) have difficulty (or trouble) in doing sth.
　　该句型意为“做…有困难”。其中的in可以省略；其中的difficulty和trouble是不可数名词，不能有复数形式。也可以用there is difficulty(or trouble) in doing sth.表达相同的意思。
　　There was little difficulty in finding him.
　　3) keep (sb. or sth. ) busy doing sth.
　　该句型意为“使…一直忙着做某事”。需注意的是虽然busy with doing sth.和busy in doing sth.都是正确的，但考题中常考busy doing sth.句型。但如果busy后面跟的是名词，则要用busy with sth。
　　We are busy preparing for the examination.
　　4) feel like doing sth.
　　该句型意为“想做某事”，且feel like后只能跟动名词，而不能跟动词不定式。此外，feel like后还可跟名词或代词，表示“想要某物”。
　　I was so angry that I felt like throwing something at him.
　　I feel like beer tonight.