In the northern hemisphere, convection creates large convection cells that produce winds.

a. one; global.
b. six; global.
c. three; global.
d. four; westerly.

hint: solar energy hits earth at different angles.

one characteristic that is shared by all is a soft body. many

of these invertebrate animals also have an outer shell to protect their

body. oysters, clams, snails, and mussels are all mollusks. so are octopuses, squids, and slugs. mollusks live on land and in freshwater.

other quantities, called derived quantities, are defined in terms of the seven base quantities via a system of quantity equations. the si derived unitsfor these derived quantities are obtained from these equations and the seven si base units.