Developed by Edward Jenner, the first true vaccine was designed to protect against this disease
They're the 2 lines of latitude lying 23 1/2 degrees north & south of the Equator
This ninth planet's unusual orbit sometimes brings it closer to the sun than the eighth planet
It's the ratio of the amount of water vapor in the air to the amount the air can hold at that temperature
A parasitoid differs from a parasite in that this eventually happens to its host
The acceleration of falling objects varies from place to place because of variations in this force
It's the property of a body that opposes an electric current moving through it
These respiratory organs of aquatic animals occur in oysters & some insect larvae as well as in fish
Used to control glaucoma, a trabeculectomy is a procedure that reduces pressure in this organ
The number of these dark patches visible on the sun's surface varies from a few to several hundred