1. Although my alarm clock did not go off, Ucausing me to arrive no more Uthan ten minutes late. it did not cause me to arrive more.
2. Eating foods rich in carbohydrates before a race is common among marathon runners, Uall of themU need reliable energy sources for peak performance. of whom need.
3. ULos Angeles’s freeways, usually busier and more crowded than those of other cities, are clogged almost twenty four hours a day, contributing to the city’s pollution problem.
Right! 点评：首先，无论指代，主谓还是时态，本句没有问题，且又是顺叙，直接用“Los Angeles’s freeways”而不用“the freeways of Los Angeles”，所以是正确的。
4.(常考题：修辞对象)Set in the sixteenth Ucentury, modern audiences enjoyed the contemporary opera Galileo Galilei written by Philip Glass.U century, Philip Glass’s contemporary opera Galileo Galilei has enjoyed great success with modern audiences.
点评：注意形容的对象和形容的部分要相邻为好，同时注意顺叙，用“Philip Glass’s contemporary opera”而不是“the contemporary opera Galileo Galilei written by Philip Glass.”
5. UWhenever television is denounced by viewers for its violence, they call Uon the department of standard and practice to take action.Whenever viewers denounce television for its violence, they call
点评： 这样改使句子十分完整，谁“denounce”?是“viewers”，且viewers call…for practice. 同时还是要强调顺叙，不要用被动态。主语为“viewers”而不是“television”