Making a connection: variable stars change their brightness periodically. which of our daily life devices, instruments etc. change their brightness or/and size alike variables. give examples, explain differences and similarities. (astronomy)

The solstices and equinoxes, and the number of hours of daylight associated with each, are major factors in the seasons. use the drop-down menus to identify the month when each of these events occurs. the winter solstice in the northern hemisphere: an equinox in both hemispheres: the summer solstice in the northern hemisphere:

You could say the relative location of washington, d.c.

One disadvantage that darwin faces today is w. enemy attacks x. natural disasters y. lack of land bridge z. high population density