They travel at speeds of up to 30 knots.

　　他們以高達(dá)30節(jié)的航速行進(jìn)。

　　Our travel plans are still up in the air.

　　我們的旅行計劃尚未決定。

　　You can book at your local travel agency.

　　你可以在當(dāng)?shù)氐穆眯猩缬喥薄?/p>