单项选择题

Warm-blooded animals maintain a steady temperature by ______.

A．storing heat in their body cells
B．regulating the amount of heat produced
C．regulating the amount of heat given off
D．constantly replacing lost surface heart

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热门试题

单项选择题

The selection says that every animal is a living radiator because it ______.

A．produces heat in its body cells
B．burns fuel to produce heat
C．gives off heat through its skin
D．requires oxygen to produces heat

单项选择题

The writer is amazed by the black spider' s ______.

A．delicate construction
B．ability to live in such varied environments
C．unusual intelligence
D．ability to withstand extreme cold