单项选择题
The attack of the World Trade Center will leave a （）impression on those who have witnessed the explosion.
A. long B. forever C. lasting D. lively
单项选择题 Don't rest on your laurels;（）your success and start looking for new markets now.
单项选择题 Because Edgar was convinced of the accuracy of this fact, he（）his opinion.
单项选择题 Our visual perception depends on the reception of energy reflecting or radiating from（）which we wish to perceive.
