动名词（续1）
5. 几个句型 (1)There is no use (in) doing …或It is (of) no use doing …“做…是没有用的” There is no use (in) grounding(使接地) this point(点). (2)人+ spend +宾语+ on sth. /(in) doing sth.“在…上花费…” They spent(花费) a lot of time on this problem(题)./They spent a lot of time (in) solving this problem. (3)人+has/have + difficulty/trouble + with sth. /(in) doing sth. We have some difficulty with this experiment. /We have some difficulty (in) doing this experiment.
6．反射式动名词（其定义与反射式不定式雷同） This book is worth reading. [It is worth reading this book.] This computer needs repairing(修理). [This computer needs to be repaired.] This work piece(工件) is too complex(复杂的) to finish(完成) machining(加工) in so short a time. An old house badly(很差) maintained(维护) would not be worth spending(花费) money on.
二、动名词复合结构 1. 构成（“逻辑主语+动名词”） 物主代词(its, their等） 名词所有格 + 动名词(短语) 名词通格(常见) 2. 功能：常见作“介词宾语”，还可作“主语、宾语、表语” (1)作介词宾语 The wonder(奇妙) of the computer lies in(在于) its being very quick(迅速的)and accurate(精确的) in doing complicated(复杂的) calculations. We know of the earth’s acting(作用) as a big magnet(磁体).
This effect(效应) is due to(由于) V being zero(零) when no signal(信号) is present(存在的). This is an example of magnetism(磁) being converted(转变) into electricity(电). (2)作主语 Like poles(磁极) repelling(排斥) each other is a very useful physical(物理的) phenomenon(现象). (3)作宾语 In this way we can prevent(防止) its being reset(复位) under the I=1 condition(情况).
(4)作表语(极少见) The first step(步) in a nuclear(核的) reaction(反应) between two colliding(相撞的) nuclear particles(微粒) is their joining(结合) together to form(形成) a compound(合成的) nucleus(原子核).