n.定位焊；緊釘

n.變換航向

動詞tack的現(xiàn)在分詞形式.

His brother is sharp as a tack; he got100 on every test. 他弟弟十分聰明伶俐，每次考試都得100分。

By tacking about, we were able to avoid the enemy guns. 我們擺動著船帆不停地調轉船頭，才得以躲過敵人的炮彈。

n.攻擊；抨擊

v.攻擊；抨擊；發(fā)動攻擊；（疾病）侵襲

n.堆垛；分層

動詞stack的現(xiàn)在分詞形式.