Upright gait.
Firstmate
Except for Primates, most Mammals have four legs.
Primates
Yes, they are placental mammals. Most mammals are placental. The other two options are marsupial mammals (mammals with a pouch) and monotreme mammals (mammals that lay eggs).
which adaptation do you think is the the most important
A primate, as both primates and rodents are mammals.
Primates are characterised by large brains relative to other mammals. Their eyes face forward, giving them stereoscopic vision and vision is the sense they rely on most rather than smell like other mammals. Most primates with a few exceptions have opposable thumbs and have developed adaptations to climb trees. Primate babies take a long time to mature because of their brain size, relative to non-primates. Non-human primates have oestrus cycles and many species display swellings during their fertile period.
Horses and cows suck up water rather than lap it with their tonges. Snakes also drink in this way, but they aren't mammals.
The Bali tigers preyed upon most mammals that they found around them including rodents and small primates
Mammals
Most species of animals have adapted well to tropical regions. Predators have developed the ability to swim, and primates have evolved to be nocturnal feeders.
Hi
Menstruation happens when the endometrium gets shed through the vagina of the female mammal. It is most common in primates. Other mammals go through a cycle known as the Estrous Cycle where the endometrium is reabsorbed into the body.