What are two Earth irregularities that can change the intensity of the seasons?

Which technically is nasa developing that will astronauts reach mars

Adigestive system that is a series of tubes beginning at the mouth and ending at the anus is a digestive system.

6. in domesticated cats, the following are independently assorting: normal ears (t) is dominant to tufted ears (t); curved whiskers (c) is dominant to straight whiskers (c); the presence of six toes (s) is dominant to five toes (s); gene for hair length is an x-linked codominant. the three phenotypes for hair length are long (xhxh), medium (xhxh), and short (xhxh); medium is the heterozygous condition. given two parents: ttccssxhxh x ttccssxhy how many different gametes could be formed in the female cat with respect to these four traits? how many phenotypes are possible in the offspring from this mating?