【推荐2】Wilbur and Orille Wright are brothers famous for inventing the first aeroplane. Their interest in flight     1     (start) on the day when their father brought home a toy helicopter for them. It was made of paper and wood. The boys played with it until it broke, and then made their own     2     (replace) it. When they were older, they owned a bicycle shop where they started producing and selling their own bikes. This provided them with the money to pay for their experiments in flight. Eventually, they built their     3     (fly) machine.

The question of     1     invented the computer cannot be answered with a single name. Throughout history, many different people have helped in the development of this     2    (value) machine.And many date the first important     3    (invent) to the fourth century BC when the abacus was developed.

It could be said that the first computer     4     could store programs was the 1949 Electronic Delay Storage Automatic Calculator.It     5    (create) by Maurice Wilkes.From this point forward, many developers helped to make various types of computer.

In the early 1970s, many skilled inventors     6    (include) Bill Gates, Steve Jobs，and Steve Wozniak did much to develop personal computers in the form of PCs and Apples. By the 1990s, ownership of PCs became common as production (生产) grew     7    (expensive) than before. Also, with the development of technology, the size of these machines became smaller so that they could     8    (easy) be used in homes.

There is no doubt     9     there are so many thinkers and inventors who helped to develop the computer.There are even legal battles (斗争) over who should be considered as the primary inventors. As     10     matter of fact，it is their joint (共同的) efforts that led to the development of this most useful machine.

On March 31, the Eiffel Tower, one of the world’s most visited and recognizable places of interest, celebrated the 130- year anniversary (周年纪念日) of its opening.

It was only supposed to exist for 20     1     (year). Maybe Parisians decided it was     2       (easy) to just leave it in place than pull it down. It looks like they made the right choice. More than 250 million people     3     (pay) a visit to the tower so far, according to     4     (it) official website.

Designed by French Gustav Eiffel, the tower was meant     5     (serve) as the entrance to the 1889 World Fair in the     6     (begin). It took just over two years to build it. Although it is popular now, not all French people liked     7     tower when it opened. However, the visitors to the 1889 World Fair found it     8     (entertain) to visit the Eiffel Tower. Two million people visited it during the fair. It then became useful as a radio antenna (天线) during the First World War.

Tourists have a choice when they climb the tower. They can either walk 1, 665 steps to the top     9     use one of the elevator cars from 1899. Once tourists reach the top,     10     the Eiffel’s office is, they can have a drink in the tower’s top-floor champagne bar. Today, the tower stands as a symbol of France.

The Dujiangyan is the oldest man-made water system in the world, and a wonder in the development of Chinese agriculture. Built over 2,200 years ago in     1     is now Sichuan Province in Southwest China, this amazing engineering     2    (achieve) is still used today.

In ancient times, the region     3     Dujiangyan now stands suffered from regular floods from the Minjiang River.     4    (help) the victims of the flooding, Li Bing, the region governor, together with his son, decided to find    5     solution. Li designed a series of channels built at different levels along Mount Yulei that would take away the floodwaters while     6    (leave) the river flowing naturally. Much     7    (good), the extra water could be directed to the dry Chengdu Plain, making     8     suitable for farming.

Once the system finished, no more floods happened and the people were able to live     9    (peaceful). Today, Dujiangyan is     10    (admire) by scientists from around the world because of one feature. Unlike modern dams, where the water is blocked with a huge wall, Dujiangyan still lets water flow through the Minjiang River naturally, making the ecosystem (生态系统) and fish populations exist in peace.