Generalized global air circulation and precipitation patterns are caused by

How does the image distance (di) of a convex lens compare with the image distance of a concave lens? a. the image distance of the convex lens is positive, and that of the concave lens is negative. b. both are negative for a virtual image. c. both are positive for a virtual image d. the image distance of the convex lens is negative, and that of the concave lens is positive.

Aregion of space in which a measurable gravitational force is indicated by the force exerted on a test mass is called

What was the first instrument to ever record an earthquake?