Of all the water on our planet, ... is found underground: a. hardly any of it b. about half of it c. most of it

Adult giraffes remain standing ... : a. some of the day b. all day c. most of the day

An individual blood cell makes a whole circuit of the body in ... : a. nearly 60 seconds b. nearly 45 seconds c. a few minutes

In "direct current" the electrons ...: a. move in only one direction b. move in both directions c. don't move at all

When we breathe out, ... : a. most of that air is oxygen b. none of that air is oxygen c. some of that air is oxygen

Helium gas can be found ... : a. only in liquid form b. in neither liquid nor solid form c. in both liquid and solid form

The human brain can continue to live without oxygen for nearly ...: a. nearly 2 minutes b. nearly 6 minutes c. a few hours

Snakes eat ... : a. only other animals b. either other animals or eggs c. either other animals or fruit

In our solar system, ... : a. neither Pluto nor Neptune are now considered to be planets b. both Pluto and Neptune are considered to be planets c. Pluto is no longer considered to be a planet

A diamond can be destroyed ... : a. by either intense heat or acid b. by both intense heat and acid c. only by intense heat