Earlier this year, British explorer Pen Huddle and his team trekked for three months across the frozen Arctic Ocean, taking measurements and recording observations about the ice.
There were four Japanese aircraft carriers destroyed in the Battle of Midway and within the past week the remains of two of them have been located by a team of deep sea explorers.
The two areas are low-lying regions which reportedly are easier for first time Mars explorers to land on, and either one provides a good source of deposits to understand the red planet's evolution.
The British explorer Wilfred Thesiger crossed it in the mid-20th century and he said it was named Rub al-Khali or " Empty Quarter" because it's so enormous and so desolate.
The law gives Britain and America the power to grant or deny licenses for explorers to send submersibles inside the wreckage and to remove any artifacts they find outside of it.
When I first learned about caravels, which were those small ships that Portuguese explorers used to travel down the African coast in the 15th century, I had a hard time remembering that name – caravels.
Spanish explorers claimed to see: " Cities that glistened in white." " Great quantities of maize and oats." " A town of disproportionate size… " " and a chief with gold idols… and other riches" .
That's more than six miles below the waves and it's only 63 feet shallower than what's believed to be the world record depth that was reached by an American explorer last year.
六级听力真题精听 
4
海域探险。
困苦。
着艰苦
奇怪的大毒蛇，该湖泊后来以他的名字命名-尚普兰湖。
一次了解到“帆船”(caravels)时，我很难记住这个词。“caravel”是葡萄牙
