He told the brainy, sensitive, vegetarian girl next door that she couldn't come over because they were murdering polar bears.(他告诫这个住在他隔避的聪明、敏感、素食的女孩，她不能过来，因为他们正在谋杀北极熊。)
The polar vortex is a system of wintertime winds.(极地涡旋是冬季风形成的一个风系。)
In ''On Thin Ice'', Richard Ellis, a writer and illustrator, paints a natural history of the icon of the north, the polar bear.(在《薄冰之上》一书中，作家兼插画家理查·埃利斯描绘了北极图标，北极熊的自然史。)
Scientists have long suspected that several factors lead to greater temperature swings at Earths polar regions than elsewhere.(长期以来，科学家们一直怀疑有几个因素导致了地球极地地区比其他地区更大的温度波动。)
This is the result of the four polar bonds clustering symmetrically in space.(这是四个极性键按空间对称聚集的结果。)
Second, the polar atmosphere is thin, so little energy is required to warm it.(其次，极地的大气层很薄，所以加热它所需要的能量很少。)
Biologists calculate that there are about 20,000-25,000 polar bears worldwide.(生物学家估计，全世界大概有2万至2万5千只北极熊。)
Although polar bears' locomotion is similarly inefficient, polar bear cubs walk along with their mother.(尽管北极熊的运动能力同样低下，北极熊幼崽还是和妈妈一起前行。)
The Canadian Arctic is a vast, treeless polar desert that's covered with snow for most of the year.(加拿大的北极是一个广阔的、没有树木的极地沙漠，一年中大部分时间都被雪覆盖着。)
