When food is being mechanically digested, it is being (1) changed into another substance
(2) made smaller in size
(3) converted into energy
(4) excreted from the body

(2) made smaller in size

Explanation:

Mechanical digestion involves physically breaking the food into smaller pieces.

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.

feral cats are estimated to eat tens of millions of native animals each night in australia