fortune的副词形式

　　Fortunately, she knew at once what to do.

　　幸运的是，她立刻知道该做什么。

　　Fortunately, the clue is in the language itself.

　　幸运的是，线索就在语言本身。

　　Fortunately, the collision hypothesis is testable.

　　幸运的.是，碰撞假说是可验证的。