oven前面是a还是an

前面是an，例如：

1.The inside of the box will be like an oven.盒子的内部就像烤箱一样。

2.Jacqueline Hansson from Amy Cleaners shows us how to clean an oven so that it gleams with pride.艾美清洁中心的Jacqueline Hansson向我们展示怎样清洁烤箱，让它重新散发出光彩。

3.Open a window, it's like an oven in here!打开窗户。这儿热得像火炉！