luckily是什么词性

副词词性，意思是幸好、存在，例如：

1.Luckily he had insured himself against long-term illness.幸运的是，他为自己投保了长期病险。

2.Luckily, nothing valuable was stolen.幸运的是，没有贵重物品失窃。

3.Luckily for us, the train was late.我们真凑巧，火车晚点了。