31.   But thousands of homes are behind buildings or hills and cannot receive those signals.

32.   By transmitting pulses of microwave energy toward the ground and receiving signals that are reflected back, the radar produces images of the shape and nature of the surface.

33.   Cells secrete chemical signals to influence the behavior of other cells, and they receive signals through special receptors embedded in their surfaces.

34.   Consumers will also need to lease a device to receive cable signals.

35.   Cynthia Brumfield, an industry analyst with Paul Kagan Associates, said the technology will only work with newer cable boxes that have been programmed to receive the signal.

36.   Currently, cable companies have facilities that receive signals by satellite that then flow over their local networks.

37.   During World War II his work on microwave theory helped develop the technology to transmit and receive radar signals.

38.   Eighty percent of the Afghan population will be able to receive the signal for the two-hour program in Pashto and Dari, according to the European Commission.

39.   During the transition years, broadcasters plan to continue sending programs over their present analog transmission systems to households that can receive the signals.

40.   Even with the difficulties of receiving a signal from what is still, admittedly, an experimental station, the advantages of digital HDTV are immediately obvious.