一只苍蝇，有几只眼睛？

A housefly has five eyes. 一只家蝇有五只眼睛。 Two big eyes are on the sides of its head. 两只大眼睛长在头的两侧。 These are called compound eyes. 它们叫作复眼。 Each compound eye is made of thousands of tiny lenses. 每只复眼都由几千个小镜片组成。 Three small eyes sit on top of its head. 头顶上还有三只小眼睛。 The small eyes help the fly see light and movement. 小眼睛帮苍蝇感知光线和动静。 That is why it is so hard to catch a fly. 这就是苍蝇那么难打中的原因。