单项选择题
The destruction of the Twin Towers in New York City （）shock and anger not only throughout America but also throughout the whole world.
A. enveloped B. summoned C. tempted D. provoked
单项选择题 I want to（）a slightly different issue which is related to Anna's question earlier about our different meanings of open-ended problems.
单项选择题 The problem has been（）my mind all day.
单项选择题 Sometimes（）matters may result in surprising large effects.
