What component of volcanic eruptions can block sunlight over large areas?
a) water vapor
b) lava
c) sulfur dioxide
d) ash

Hurry which of these is true about index fossils? a) are very scarcely found b) used as guides in relative dating c) found in the youngest layer of the rock d) used as reference points in absolute dating

What type of pollution does household garbage cause

The (blank) states that all loving things are made of cells.