Centering a block or image. Sometimes it is not the text that needs to be centered, but the block as a whole. Or, phrased differently: we want the left and right margin to be equal. The way to do that is to set the margins to 'auto'.In case of a browser, that means the browser window). So centering an element in the viewport is very simple. Here is a complete example. (This example uses HTML5 syntax.). You can see the result in a separate document. The 'margin-right: -50%' is needed to compensate the 'left: 50%'.
Slugs and snails share many similar features. However, the most apparent difference between the two is that snails carry coiled shells on their backs whereas slugs do not contain these shells. A shell of snail is composed of calcium carbonate and it keeps growing with the growth of snail.Both produce mucous for retaining the moisture.owever, the most apparent difference between the two is that snails carry coiled shells on their backs whereas slugs do not contain these shells. A shell of snail is composed of calcium carbonate and it keeps growing with the growth of snail. Both produce mucous for retaining the moisture.
The Class Gastropoda includes snails and slugs. Most gastropods have a single, usually spirally coiled shell, but the shell is lost or reduced in some groups. Many snails have an operculum, a plate that closes the gastropod's opening.Shelled gastropods have mantles, while those without shells have reduced to absent mantles. Gastropods have a muscular foot used for creeping in most species. In some, the foot is modified for swimming or burrowing.Most gastropods have a well-developed head that includes eyes at the end of one to two pairs of tentacles.any snails have an operculum, a plate that closes the gastropod's opening. Shelled gastropods have mantles, while those without shells have reduced to absent mantles. Gastropods have a muscular foot used for creeping in most species. In some, the foot is modified for swimming or burrowing.