Identify the true statement. choose one:
a. time zones are set in relation to the time at the astronomical observatory in greenwich, england.
b. time zones are 15° of latitude wide.
c. denver (latitude 40°n, longitude 105°w) is 10 time zones away from greenwich, england (latitude 51°n, longitude 0°).
d. the second (as a unit of time) is defined in terms of energy changes within the chromium atom.

A. Time zones are set in relation to the time at the astronomical observatory in Greenwich, England.

Explanation:

Time zones around the world are set and divided on the basis of the line that is drawn along the prime, meridians and this marks the division of the two-sphere as western and eastern longitudes. Thus the place on the Greenwich England is said to be taken as the prime meridian as the basis of astronomical observations It is observed as the zero degrees meridian as GMT. Is a 5.5 mile in relation to the mean solar time. As most of this zone are considered as ahead and after GMT.

This is all you, but i can give you some topics that you could try. if it rained when you want to do something outdoors, it 'limits' that human activity. maybe you want to do an experiment that goes throughout the whole year and you have to have above freezing the entire year. this 'limits' your activity. i thought of those just off of the top of my head. something that gets to me that might be getting to you is you are thinking too hard about what to do. think simply, and if it is too simple, then bump it up just a little bit.