The English teacher isn't here. She ________ to the office.
A:has been
B:has gone
C:went
D:did go
商周时期青铜铸造业高度发展,技艺精湛、气势浑厚的青铜重器象征着那个时代灿烂辉煌的文明,____是目前世界上已发现的古代最大的青铜器。
-- I had a pleasant winter vacation with my family in the north.
-- ______.
如图,要测量河岸相对的两点A、B的距离,先从点B出发与AB成90°角方向,向前走50m到C处立一根标杆,然后方向不变继续朝前走10m到D处,在D处转90°沿DE方向再走17m,这时A、C、E在同一直线上.问A、B间的距离约为多少?