describe why many nations impose trade restrictions,if free trade is the best policy.用英文回答

describe why many nations impose trade restrictions,if free trade is the best policy.用英文回答
describe why many nations impose trade restrictions,if free trade is the best policy.用英文回答

describe why many nations impose trade restrictions,if free trade is the best policy.用英文回答
Not all nations will be happy to accept free trade.
Neither developed countury nor developing one.
They all want more benefits,so I can say that none will not impose trade restrictions if free trade is the best policy.

I don't know