题目

It was my birthday last Thursday. I decided to __36__   by inviting a few friends out to supper. I chose a restaurant in a __37__   part of town. It is one of my favorite restaurants because the food is good and the waiters are friendly. It is __38__   ever crowded, because not many people know about it, so it is not usually __39__ to book a table. In any case, Thursday is not a busy evening __40__.     When we entered the restaurant, we were surprised to find it completely __41__. I looked around but not __42__table was free. One of the waiters recognized me. He came a已知f（x）=Asin（ωx+φ）（A＞0，ω＞0）满足条件f（x+）+f（x）=0，则ω的值为（ ）A．2πB．πC．D．