1 These can be two Excel files or an Excel File and a Microsoft Word file for example. 2  Press and hold down the Alt key on the keyboard. 3  Press and release the Tab key on the keyboard without letting go of the Alt key. 4  The ALT-TAB Fast Switching window should appear in the middle of your computer screen. Open at least two files in Windows. 2  These can be two Excel files or an Excel File and a Microsoft Word file for example. 3  Press and hold down the Alt key on the keyboard.
Merge this question into. Split and merge into it. Answer by Quirkyquantummechanic. Confidence votes 77.6K. Almost all of a mollusk shell is composed of calcium carbonate. It may take a few different forms and thereby appear differently, but CaCO3 is the main material in the shell.
Section 1 - Mollusks. Mollusks are invertebrates with soft, unsegmented bodies that are often protected by a hard outer shell. In addition to a soft body often covered by a shell, a mollusk has a thin layer of tissue called a mantle that covers its internal organs, and an organ called a foot.Mollusks have bilateral symmetry and a digestive system with two openings.Most species of mollusks have an open circulatory system, in which the blood is not always inside blood vessels. Most mollusks that live in water have gills, organs that allow oxygen from the water to enter the body.lams, oysters, scallops, and mussels are bivalves. Bivalves are mollusks that have two shells held together by hinges and strong muscles. Bivalves live in all kinds of watery environments. Bivalves do not have radulas.