In the Focus Section About "Weather Radar," the Latest Improvement

Multiple Choice

In the Focus section about "Weather Radar," the latest improvement on the U.S. Government's radar NEXRAD system is the ________.

A) dual polarization
B) incorporation of data from airplanes
C) ability to detect all tornadoes
D) first use of the Doppler effect
E) warning sirens are electronically hooked to the radar