如图,在一次数学课外实践活动中,小聪在距离旗杆10m的A处测得旗杆顶端B的仰角为60°,测角仪高AD为1m,则旗杆高BC为____m(结果保留根号).
____,可以无悔矣,其孰能讥之乎?(王安石《游褒禅山记》)
She likes eating____(fish)very much.
例如468+439,精确计算468+439=907,用整十或整百数估算470+440=910
578+207,精确计算578+207=____,用整十或整百数估算____+____=____