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

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

Once the system     8    （finish）, no more floods happened and the people were able to live     9    （peaceful）. Today, Dujiangyan is admired by scientists from around the world because of one feature. Unlike modern dams,     10     the water is blocked with a huge wall, Dujiangyan still lets waterflow through the Minjiang River naturally, making the ecosystem（生态系统）and fish populations exist in peace.

Plovdiv is situated in south-central Bulgaria on the two banks of the Maritsa River. The city has historically developed on seven hills, some of     1     are 250m (820.21 ft) high. Because of these hills, Plovdiv is     2    (typical) referred to in Bulgaria as “The city of the Seven Hills”. Plovdiv’s history     3    (date) back to 6000 BC. Though originally it was     4    Thracian city, Plovidiv has been ruled by many empires over centuries. Later it       5    (conquer) by the Romans. Only in 1885 did the city become part of Bulgaria. Nowadays it’s the second     6    (large) city in Bulgaria and it’s a significant economic, educational and cultural center.

Plovdiv remains a popular     7    (choose) for vacation travel. I have been obsessed with the city     8    years. Last summer I was lucky     9    (spend) a couple of days in this city and I just fell in love with its narrow paved streets and neat beautiful house! The Old Town is definitely worthy     10    (see). It is overwhelmed with restaurants, workshops and museums that were previously famous houses.

In human history, many ancient and splendid civilizations were born and died. China is the only country     1     uninterrupted human civilization. Chinese civilization was born on the shores of the Yellow River. And the rich land     2     Chinese civilization began is Henan Province.

The Yellow River goes across     3     (center) Henan. It is China's main north­to­south and east­to­west artery(干线)．China's most ancient tribal     4     (lead), the Yellow Emperor and the Yan Emperor, were born here. Even today, Chinese people all over the world still     5     (proud) call themselves the descendants(后裔) of these two emperors.

The river holds     6     unshakable position in the heart of every Chinese,     7     (respect) by every generation and called “the Mother River”. With intelligence, hard work and determination, Chinese descendants pursue co­existence and common prosperity on this land. The 5,464­km­long Yellow River breaks the last barrier and flows into the broad plain,     8     (form) the cradle(摇篮) of Chinese civilization.

Till now, the Yellow River     9     (raise) 13 dynasties' capital Luoyang, 8 dynasties' capital Kaifeng and the biggest economic center in     10     (it) area—Zhengzhou.

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

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

Once the system was finished, no more floods occurred and the people were able to live     7    (peaceful). Today, Dujiangyan is admired by scientists from around the world because of one feature. Unlike modern dams     8     the water is blocked with a huge wall, Dujiangyan still lets water flow through the Minjiang River naturally,     9     (enable) ecosystem(生态系统) and fish populations to exist     10     harmony.