The US border with Canada is the ______ in the world.A．longest coastal borderB．longest def

If the experiment succeeds or fails, it will provide us with valuable experience, which is

The US border with Canada is the ______ in the world.A．longest defended borderB．longest un

If Quebec was separated from Canada, the two pacts with US ______.A．should be discussed ag

According to the passage, what is the beginning of "with us" era？A．The invention of the fi

The massive waterfalls which straddle the international border separating Canada and the U

Which of the following lakes does Canada share with the United States？A．Lake Winnipeg.B．Th