The vernal equinox is:
The moon completes a revolution around the earth approximately every:
Carcinogens are chemicals that cause:
A paramecium is:
What large halogen is essential for the function of the thyroid gland?
Muscles attach to bone with:
Atoms are most tightly packed in:
Blood leaving the lungs is:
The longest river in the world is:
A meter consists of:
It's impossible for the sun to turn into a black hole because:
Electrons are particles that are:
The chamber of the heart that pumps blood to the lungs is called the:
The atomic number of an atom is determined by:
The smallest part of an element that still acts like an element is:
Mitosis is a process of:
When added to a cloud's name, which of the following means rain?
The movement of particles from an area of high concentration to an area of lower c...
The instrument used to measure wind speed is:
Electric charges can be: