There used a post office at the corner of the street.A．to beB．to beingC．to haveD．to having 题目和参考答案——青夏教育精英家教网—

题目内容

20.There used__________a post office at the corner of the street.

A．to be

B．to being

C．to have

D．to having

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There used to be a church in the past , ____ ?

A . isn''t there B . didn''t there C . usen''t it D . used not it

There used to be a church in the past , ____ ?

A . isn''t there B . didn''t there C . usen''t it D . used not it

E
Paynes Prairie
Have you ever heard of Paynes Prairie? It is one of the most important natural and historical areas in Florida. Paynes Prairie is located near Gainesville. It is large, 21 000 acres. This protected land is called a preserve. The Florida Park Service manage the preserve.
The Paynes Prairie basin was formed when limestone dissolved and the ground settled. It is covered by marsh(沼泽)and wet prairie vegetation. There are areas of open water. During brief periods it has flooded enough to be considered a lake. Except for that, the basin has changed little through time.
Man has lived on Paynes Prairie a very long time. He lived there as far back as 10000 B. C. At one time, the Seminoles lived there. The prairie is thought to have been named after King Payne, a Seminole chief. During the late 1600s, the largest cattle ranch in Florida was on Paynes Prairie. Today, Paynes Prairie is preserved land. It is occupied by visitors and Florida Park Service employees.
William Bartram visited Paynes Praire. Bartram was the first person who described nature through personal experience as well as scientific observation. He lived 200 years ago. He visited Paynes Prairie in 1774. At that time he described it. He called Paynes Prairie the "great Alachua Savannah."
Most of the animal life, which Bartram described, is still here. A large number of sand hill cranes, hawks and waterfowl are here in winter. The animal diversity is increased by the presence of pine flatwoods, hammock, swamps and ponds.
The Paynes Prairie Preserve State Park is open year round. The Florida Park Service works hard so that the park will appear as it did in the past. It offers many opportunities for recreation. At the park you can camp and picnic. You can hike and bike. You can boat and fish. You can ride on horse trails. And you can see lots of nature and wildlife. You can see Florida as it was in the early days.
Paynes Prairie is a part of our Florida history. It is an example of our Florida natural resources. It is a place for recreation. Paynes Prairie is an important experience of the Real Florida.
57. How was the Paynes Prairie basin formed?
A. By the Seminole Indians.
B. By the Florida Park Service.
C. From dissolved limestone and the ground settling.
D. From lots of flooding and wet prairie vegetation.
58. The underlined word "diversity" means “_______.”
A. variety B. society C. population D. area
59. All of the following are true EXCEPT that _______.
A. Paynes Prairie has changed little through time
B. Paynes Prairie is covered by wet prairie grasses
C. there used to be a big cattle farm on Paynes Prairie
D. William Bartram was the first person~ to visit Paynes Prairie
60. The purpose of the passage is to_______.
A. call on people to protect wildlife
B. attract people to this preserved park
C. show you the formation of Paynes Prairie
D. introduce the recorded history of Paynes Prairie

A team of engineers at Harvard University has been inspired by Nature to create the first robotic fly. The mechanical fly has become a platform for a series of new high-tech integrated systems. Designed to do what a fly does naturally, the tiny machine is the size of a fat housefly. Its mini wings allow it to stay in the air and perform controlled flight tasks.

“It’s extremely important for us to think about this as a whole system and not just the sum of a bunch of individual components (元件),” said Robert Wood, the Harvard engineering professor who has been working on the robotic fly project for over a decade. A few years ago, his team got the go-ahead to start piecing together the components. “The added difficulty with a project like this is that actually none of those components are off the shelf and so we have to develop them all on our own,” he said.

They engineered a series of systems to start and drive the robotic fly. “The seemingly simple system which just moves the wings has a number of interdependencies on the individual components, each of which individually has to perform well, but then has to be matched well to everything it’s connected to,” said Wood. The flight device was built into a set of power, computation, sensing and control systems. Wood says the success of the project proves that the flying robot with these tiny components can be built and manufactured.

While this first robotic flyer is linked to a small, off-board power source, the goal is eventually to equip it with a built-in power source, so that it might someday perform data-gathering work at rescue sites, in farmers’ fields or on the battlefield. “Basically it should be able to take off, land and fly around,” he said.

Wood says the design offers a new way to study flight mechanics and control at insect-scale. Yet, the power, sensing and computation technologies on board could have much broader applications. “You can start thinking about using them to answer open scientific questions, you know, to study biology in ways that would be difficult with the animals, but using these robots instead,” he said. “So there are a lot of technologies and open interesting scientific questions that are really what drives us on a day to day basis.”

(392 words)

1.The difficulty the team of engineers met with while making the robotic fly was that __________.

A．they had no model in their mind

B．they did not have sufficient time

C．they had no ready-made components

D．they could not assemble the components

2.It can be inferred from paragraphs 3 and 4 that the robotic fly __________.

A．consists of a flight device and a control system

B．can just fly in limited areas at the present time

C．can collect information from many sources

D．has been put into wide application

3.Which of the following can be learned from the passage?

A．The robotic flyer is designed to learn about insects.

B．Animals are not allowed in biological experiments.

C．There used to be few ways to study how insects fly.

D．Wood’s design can replace animals in some experiments.

4.Which of the following might be the best title of the passage?

A．Father of Robotic Fly

B．Inspiration from Engineering Science

C．Robotic Fly Imitates Real Life Insect

D．Harvard Breaks Through in Insect Study

There used to be a small school, ______ ?

A．was there

B．wasn’t it

C．usedn’t there

D．usedn’t it

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