题目

While it is impossible to live completely free of stress, it is possible to prevent stress as well as reduce its effect when it can’t be avoided. 【1】Try physical activity.【2】 Running, walking, playing tennis, and working in your garden are just some of the activities you might try.Make time for yourself.Arrange time for both work and fun. Don’t forget, play can be just as important as your overall well-being as work. 【3】 Go window-shopping or work on a hobby. Allow yourself at least a half hour each day to do something you enjoy.Take care of yourself.【4】If you easily get an具有单双键交替长链(如：)的高分子有可能成为导电塑料。2000年诺贝尔(Nobel)化学奖即授予开辟此领域的3位科学家。下列高分子中可能成为导电塑料的是 A．聚乙烯          B．聚丙炔        C．聚丁烯          D．聚氯乙烯