99色精品-9色在线-99色在线-99色视频 国产欧美日产一区二区三区_亚洲精品亚洲人成在线观看_四虎在线精品永久观看_免费一级a一片久久精

單項選擇題

Error may be introduced into a magnetic compass by().

A.making a structural change to the vessel
B.a short circuit near the compass
C.belt buckles
D.All of the above

微信掃碼免費搜題