【简答题】A.To tell the crab what time it is. B.To protect the crab from the sunlight and enemies. C.To keep the crab warm. D.To be of no real use.
【单选题】Suppose the Alaskan king crab harvest is unregulated and any person with a crab boat and some diesel fuel can go offshore, lower a crab pot, and harvest king crab. As a result, this common resource is...
A.
Alaska subsidizes the purchase of crab boats.
B.
Alaska auctions a limited number of licenses to harvest king crab.
C.
Alaska removes taxes on diesel fuel, which lowers the price of diesel.
D.
The U.S. and Canadian governments remove trade barriers, which allows for more trade of products like king crab.
【单选题】The crab’s changing colour ______.
A.
tells the crab what time it is
B.
protects the crab from the sunlight and enemies
【单选题】交换机是一种___________设备.
【单选题】交换机是一种___________设备.
【单选题】The crab’s colour—changing ability was probably developed ______.
A.
in the process of evolution ( 进化 )
B.
over millions of years
C.
by the work of biologists
【单选题】Well, the crab salad's always a big ____.