l met a friend of mine---- in the street yesterdaya\ by accidentb\ by the endc\ by mistaked\by the time为什么答案是a理由越详细越好,好的有赏

l met a friend of mine---- in the street yesterdaya\ by accidentb\ by the endc\ by mistaked\by the time为什么答案是a理由越详细越好,好的有赏
l met a friend of mine---- in the street yesterday
a\ by accident
b\ by the end
c\ by mistake
d\by the time
为什么答案是a
理由越详细越好,好的有赏

l met a friend of mine---- in the street yesterdaya\ by accidentb\ by the endc\ by mistaked\by the time为什么答案是a理由越详细越好,好的有赏
l met a friend of mine---- in the street yesterday
a\ by accidentb\ by the endc\ by mistaked\by the time选a首先是选最佳答案.选项a\ by accident“偶然”,在大街上茫茫人海中“偶然地”遇见朋友是一件自然的事.选项b\ by the end词组不完整,by the end of...选项c\ by mistake在大街上“错误地”遇见朋友,表达不符合汉语.选项d\by the time后面应该有修饰这个词组的定语,因为“截止.时”