If you look at your page, you can observe that some elements come by pair: the eyes, the arms & the legs. It is the same organ, one on the left and one on the right ; they have exactly the same shape, so for practicity & to avoid to repeat twice the same style, we're not going to use their `id` to style them, but a [`class`](https://developer.mozilla.org/en-US/docs/Web/CSS/Class_selectors) ; contrary to an `id`, a `class` can be attributed to several different elements with common rulesets, and so the style defined for that class will apply to all the HTML elements that have it.
Note that you can attribute several classes to a same element ; create the class `body-member`, which set the `width` to 50 pixels and the `margin` to 30 pixels, and add it to the `class` attribute of those elements: `arm-left`, `arm-right`, `leg-left`&`leg-left`.
