Which of the following is a correct approximation of average sea-level atmospheric pressure?

HIV directly causes the death of which type of T cells?

A) helper cells B) killer cells C) memory cells D) all of these

The North Atlantic Current is an example of which of the following types of currents?

A) Eastern Boundary Current B) Equatorial Counter Current C) Northern Boundary Current D) Southern Boundary Current E) Western Boundary Current

Which of the following boxes represents a suspension?

A. Only A represents a suspension. B. Only B represents a suspension. C. Only C represents a suspension. D. Each of these could represent a submicroscopic portion of a suspension.

All of the following is true regarding shortwave radiation that reaches the earth's surface except

A) the earth's atmosphere can be heated by latent heat released through condensation, freezing, and deposition. B) heating of the atmosphere by insolation is more effective than heating of the atmosphere by land and water. C) some shortwave radiation is absorbed by ozone molecules in the stratosphere and converted to sensible heat. D) shortwave radiation is absorbed by the surface and then radiated as longwave radiation where it can later be directed downward by counterradiation.