8.Polar bears need(freeze) conditions, so they are also suffering because of global warming.

By saying "Spring is usually prime food time for 1,200 polar bears" ( Line 1, Para. 1 ), the author means that ______. A: spring is usually a good time for polar bears to carry out their mating rituals B: the polar bears usually eat a lot in the spring C: spring is generally a good time to hunt polar bears D: polar bears usually hibernate in the spring

How is the future of polar bears?

Due to global warming, thefor polar bears is shrinking, causing the number of polar bears to keep decreasing. A: habit B: habitat C: apparatus D: habitant

The polar bear evolved from brown bear ancestors.

For six months of the year, there is hardly any light at the ( ). (polar)

Polar bears have evolved bodily features to stay warm

函数plot3和polar都是三维曲线绘制函数。

使用matplotlib的pyplot模块，可以用来创建极坐标系的方法有（ ）。 A: 调用绘图区实例的add_subplot方法时设置其参数polar为True B: 调用绘图区实例的add_axes方法时设置其参数polar为True C: 调用polar方法，同时创建极坐标系并绘图 D: 调用subplot方法时设置其参数projection为“polar”

The epithelial cells of intestine are polar, what kind of connection is related to its polarity?_