The is a typical picture that NASA uses to illustrate a context of solar flares. particles acceleration occurred somewhere for some reason, and stream down to radiate some other places, either loop-top and foot points in this case.(We have to put all the observed radiations back into such a picture.)  Here are some specific issues that we need to address: colored orange is the most often discussed issues, the green is a rarely discsuused, the puple—never discussed-isotropy assumed.: First (indicate the left picture) we want to know how much the observed radiation properties are due to acceleration properties  (ultimate goal) and not due to any transport effect. Often talked about Transport—could be trap and precipitation, and etc. Good precipitation could meaning pitch angle diffusion and good trapping—weak diffusion or strong magnetic mirroring, etc. In some cases all the things in the left column could be related to each other while all the things in the right could be, but not always. In many cases we would not really know, for instance, how much is due to acceleration effect and how much is due to the transport effect.  So we got to make use of the microwave spectrum to help sorting out these issues.  So we tried to relate the spectral observation made at OVSA to the science listed up there.
	The orange stuff are usually stuff, commonly mentioned issues, The green—rarely mentioned, and the purple would be never … in my knowledge. I will mention it for the first time in this workshop.