What kind of wavelength do television signals have?
a. short
c. long
b. intermediate
d. very rapid

Television signals have long wavelengths.

Explanation:

Television wavelengths are required to be transmitted over long distances. This is only possible when the wavelength of theses signals is long.

If wavelength of signals is short then there will be difficulty in broadcasting of channels or programs.  

Thus, we can conclude that television signals have long wavelengths.

- decrease the number of plants and animals living in the water.

14 days is the half-life of phosphorus-32