某一行业有如下特征：行业的利润由于一定程度的垄断达到了较高的水平，风险因市场结构比较

已知x+y=7，xy=﹣8，下列各式计算结果正确的是[ ]

A．（x﹣y）²=91

B．x²+y²=65

C．x²+y²=511

D．x²﹣y²=567

如图所示，在研究浮力大小时，将浮于水面的盆子慢慢向下按，用力越大，盆子浸入水中的部分越多．根据以上事实，下列猜想最符合研究目的是（　　）

A．用力越大，物体排开水的体积越大

B．液体的密度越大，物体所受浮力越大

C．物体的体积越大，物体所受浮力越大

D．物体排开水越多，物体所受浮力越大

美国新总统奥巴马是黑种人，英国首相布朗是白种人，而联合国秘书长潘基文是黄种人。当今世界人种的差异最早是在什么时期出现的[ ]

A．早期猿人

B．晚期猿人

C．早期智人

D．晚期智人

Did you know that a turtle（乌龟）can lay 12 eggs in one minute? A large sea turtle lays

around 150 eggs at a time. She lays all these eggs in just a few minutes.

Large sea turtles live in the warm seas of the world. Except for when they lay their eggs,

they spend their whole lives in the water. When it is time to lay their eggs, the females swim toland. They usually return to the place where they themselves were born. How they find theirway back there is unknown.When they reach shore, the big, heavy turtles crawl slowly up to the high water mark.Using their flippers, they pull themselves along the sand. They must struggle like mountainclimbers. When they finally reach dry sand, they rest before beginning the difficult task oflaying eggs.The turtles lay the eggs in deep holes and cover them with warm sand. The sand protectsthe eggs from harm. Then the females leave them. After a few weeks, if you happened to be walking along the beach, you might see the sand begin to shake. You may see tiny black ballscoming out of the sand. The tiny heads of baby turtles!

小题1:

Which sentence expresses the main idea?

A．Sea turtles have interesting life habits.

B．Sea turtles swim to shore to lay their eggs.

C．Large sea turtles lay their eggs in special ways.

D．Sea turtles enjoy staying in the sand.小题2: Turtles bury their eggs to protect them from ____________.

A．deep water

B．danger

C．heat

D．bad weather小题3:We can conclude from this passage that ___________.

A．many turtles die while swimming to shore

B．female turtles protect their babies

C．once turtles land, they never return to the sea

D．the job of laying eggs takes great strength小题4: The writer compares turtles to climbers ___________.

A．because they lay their eggs in mountain areas

B．to give you a picture of how hard they work

C．to tell you that they like to climb

D．to show that mountain climbers are as slow as turtles

机构所在地在B市的甲建筑企业是增值税一般纳税人．当月在A县取得建筑收入50万元，则甲企业在建筑服务发生地A县（）。

A.预缴增值税1.35万元

B.缴纳城建税0.05万元

C.缴纳教育费附加0.03万元

D.缴纳地方教育附加0.03万元