题干
Look at the news! There must be someone who _____ the news.
A：leaked
B：leak
C：leaking
D：had leaked
答案(点此获取答案解析）
A
上，且OA＝4，过A作AC⊥
轴，垂足为C，OA的垂直平分线交OC于B，则△ABC的周长为 ( ) 