The population of the industrial world grew dramatically in the nineteenth century, in part because
a) improved transportation networks resulted in cheaper food and therefore better diets.
b) families did not yet know how to limit the number of births.
c) new urban centers were healthier environments than were rural villages.
d) aggressive public health programs eradicated childhood diseases.
e) all these answers are correct.

incident infrared radiation is blocked. visible and ultraviolet radiation heat   earth.

earth radiates infrared radiation. infrared radiation is blocked and heats earth. visible and shortwave radiation heat earth.

earth radiates longwave radiation

longwave radiation is reflected downward longwave radiation heats earth

a direct vote in which an entire electorate is invited to vote on a particular proposal. this may result in the adoption of a new law.