单项选择题

What can be inferred about the defence mechanisms of the sea cucumber

A．They are very sensitive to surrounding stimuli.
B．They are almost useless.
C．They require group cooperation.
D．They are similar to those of most sea creatures.

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热门试题

单项选择题

Which of the following would NOT cause a sea cucumber to release its internal organs into the water

A．A touch.
B．Food.
C．Unusually warm water
D．Pollution.

单项选择题

The author is of the opinion that ______.

A．jeans are likely to be a short-lived fashion
B．jeans are popular only in the United States
C．jeans are likely to be popular for a long time to come
D．jeans are no longer fashionable