Solar power plants that use a central receiver system or a distributed receiver system generate energy by
a)heating an oil or salt solution
b)splitting atomic nuclei
c)tracking the sun's motion
d)using the photoelectric effect

Which phrase best describes surface currents? 1. up-and-down ocean movement caused by wind 2. waves that hit the shore at an angle and transport sand 3. streams of warm water flowing through the ocean and caused by wind 4. waves that approach the shore and cause their crests to fall into their troughs

Ablastocyst is a group of cells that forms after a human egg is fertilized. the blastocyst consists of two types of cells. some of these cells will become the placenta. what do the other cells develop into?

The human genome project is devoted to mapping the general dna sequence of our species. this could lead to the development of new medicines, as well as the possibility of using gene therapy to treat certain diseases. however, there are some ethical issues surrounding the mapping of individual genomes. one concern is a) that your genes may change over time, making the project useless. b) that insurance companies could discriminate based on genetic make-up. c) that since this has never been done before, we should probably not do it now. d) that sequencing our individual genomes is so expensive, it is a counter-productive strategy.