QUES: A staple for consumers in the city is the omnipresent "mercado". Every major neighborhood in the city has its own borough-regulated market, often more than one. These are large well-established facilities offering most basic products, such as fresh produce and meat/poultry, dry goods, tortillerias, and many other services such as locksmiths, herbal medicine, hardware goods, sewing implements; and a multitude of stands offering freshly made, home-style cooking and drinks in the tradition of aguas frescas and atole.
What is the centerpiece of Mexico City's markets

ANS: mercado

QUES: Africa separated from Antarctica in the Jurassic, around 160 Ma, followed by the Indian subcontinent in the early Cretaceous (about 125 Ma). By the end of the Cretaceous, about 66 Ma, Antarctica (then connected to Australia) still had a subtropical climate and flora, complete with a marsupial fauna. In the Eocene epoch, about 40 Ma Australia-New Guinea separated from Antarctica, so that latitudinal currents could isolate Antarctica from Australia, and the first ice began to appear. During the EoceneOligocene extinction event about 34 million years ago, CO2 levels have been found to be about 760 ppm and had been decreasing from earlier levels in the thousands of ppm.
After the division from Australia, what began to appear?

ANS: ice

QUES: The avian circulatory system is driven by a four-chambered, myogenic heart contained in a fibrous pericardial sac. This pericardial sac is filled with a serous fluid for lubrication. The heart itself is divided into a right and left half, each with an atrium and ventricle. The atrium and ventricles of each side are separated by atrioventricular valves which prevent back flow from one chamber to the next during contraction. Being myogenic, the heart's pace is maintained by pacemaker cells found in the sinoatrial node, located on the right atrium. The sinoatrial node uses calcium to cause a depolarizing signal transduction pathway from the atrium through right and left atrioventricular bundle which communicates contraction to the ventricles. The avian heart also consists of muscular arches that are made up of thick bundles of muscular layers. Much like a mammalian heart, the avian heart is composed of endocardial, myocardial and epicardial layers. The atrium walls tend to be thinner than the ventricle walls, due to the intense ventricular contraction used to pump oxygenated blood throughout the body. Avian hearts are generally larger than mammalian hearts when compared to body mass. This adaptation allows more blood to be pumped to meet the high metabolic need associated with flight.
The avian circulatory system is driven by what?

ANS: four-chambered, myogenic heart

QUES: Norwegian researchers at the University of Troms have shown that some Arctic animals (ptarmigan, reindeer) show circadian rhythms only in the parts of the year that have daily sunrises and sunsets. In one study of reindeer, animals at 70 degrees North showed circadian rhythms in the autumn, winter and spring, but not in the summer. Reindeer on Svalbard at 78 degrees North showed such rhythms only in autumn and spring. The researchers suspect that other Arctic animals as well may not show circadian rhythms in the constant light of summer and the constant dark of winter.
What reinder at 78 degrees do not show circadian rythems?

ANS:
unanswerable