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

<ruby id="bpnhk"><xmp id="bpnhk"></xmp></ruby>

單項選擇題

Variation in a compass is caused by（）.

A.Worn gears in the compass housing
B.Magnetism from the earth's magnetic field
C.Magnetism within the vessel
D.Lack of oil in the compass bearings

你可能感興趣的試題

單項選擇題

This induced magnetism（）the permanent magnetism already present in the ship.

A.will add to
B.will subtract from
C.may add to or subtract from
D.will not change

單項選擇題

The variation for most given areas undergoes（）change，the amount of which is also noted on charts.

A.an annual
B.a constant
C.a variable
D.an unstable

<ins id="w7zi7"><xmp id="w7zi7"></xmp></ins>

<pre id="w7zi7"></pre>