For many parents, making sure that their children get the right amount of sleep can be     1     (stress). This is especially true during high-pressure times such as exams when students study all night for the next day.     2     (unfortunate), it is often counterproductive (适得其反的) because with fewer hours to sleep, the brain doesn’t get enough time to keep     3     they’ve studied the night before.

Poor sleep will have all sorts of negative effects on teenagers,     4     (include) the rise in blood pressure, and impatient behaviors. Without enough sleep, the brain can no longer work     5     (deal) with information properly and use information already     6     (learn).

So, how can parents help? If you think your child needs more sleep, try making gradual adjustments to their sleeping habits. So far, studies     7     (show) improvements in changing sleep patterns. And remember your children are going through     8     period of time in their lives when their brains and bodies are going through a lot of     9     (change). Not only is your job to help make a difference, but it’s also to ride the wave with them. It may not be easy,     10     they will thank you for your help eventually.

Beijing Opera,    1    (know) as China's national opera, also called Peking Opera, which originated in the late 18th century, is a combination of music, dance, art and acrobatics (杂技). It is the most influential and representative of all operas in China. It is called Beijing Opera because it is formed in Beijing. Beijing Opera has    2    history of 200 years and its origin can date back to old local operas, especially Anhui Opera,     3    was very popular in northern China in the 18th century. In 1790, the first Anhui Opera performance    4     (hold) in Beijing to celebrate the Emperor's birthday.

Later, some other Anhui Opera troupes (班子)     5     (continue) performing in Beijing. Anhui Opera was easy    6     (move) and good at absorbing the acting styles of other types of operas. Beijing accumulated many local operas,     7     (make) Anhui Opera improve quickly.

    8    the end of the 19th century and the beginning of the 20th century, after the marriage for 10 years, Beijing Opera finally formed, and became the    9     (big) of all Operas in China. We can    10     (honest) say that Beijing Opera is the most important opera in China.

For the first time, a team of refugees will compete at the Olympic Games. The International Olympic Committee (IOC) approved a plan this week for a team of up     1     10 Refugee Olympic Athletes.

This news became     2     hot topic on social media Thursday. Facebook users called the plan a “wonderful gesture” and “the     3     (great) news I’ve heard in a while.” More than 40 high-performance athletes,     4     happen to be refugees,     5     (identify) as possible Olympic athletes so far.

CNN reported Thursday that one of them is a 17-year-old     6     (swim) named Yusra Mardini. She fled Syria on a boat headed for Greece from Turkey. The boat started filling with water. Mardini and her sister got in the water and helped pull the boat and its 20 people onboard to     7     (safe).

Mardini now     8    (live) in Germany. She has received funding from the IOC for her training. The Refugee Olympic team will participate     9     the Olympic opening ceremony in Rio on August 5. The team will march out (出场) just before athletes from Brazil.

International Olympic Committee President Thomas Bach said that, “By     10    (welcome) this team of refugee athletes to Rio, we want to send a message of hope for all refugees of the world.” The United Nations says that more than 60 million people around the world are refugees.

Du Fu was a Chinese poet and politician of the Tang Dynasty. Along with Li Bai, he is     1       （frequent） called the greatest of the Chinese poets.     2    （bear） into a scholarly family, Du Fu received a     3    （tradition） Confucian education but failed in the imperial examinations of 735. As a result, he     4    （spend） much of his youth traveling. During his travels he was recognized as a poet and met other poets of the period,     5     （include） the great Li Bai. He had a strong     6     （admire） for this older, freewheeling contemporary.

Du Fu's early poetry celebrated the beauty of the natural world and bemoaned （惋惜）the passage of time. He soon began to write about war—as in “Bingche   xing”・ And with hidden satire （讽刺）9 he wrote “Liren xing",     7     speaks of the luxury （奢侈） of the court. As he matured, and especially during     8     chaotic period of 755 to 759, his poems began to sound a note of sympathy for humanity caught in the senseless war.

Du Fu's irreplaceable position in the history of Chinese literature     9     （rest） on his superb classicism。. He was an expert     10     all poetic styles current in his day, and his mastery was at its height in the lvshi, or "regulated verse”.

For those who have never tried it, scuba diving (水肺潜水) has the reputation for being     1     extreme sport, but this couldn’t be     2    (far) from the truth. Scuba diving, with all the deep breathing     3    goes with it, is almost like underwater yoga (瑜伽). It offers people a chance to forget about trouble and focus on the here and now, thus     4    (provide) a sense of calmness that is hard to find on land.

While scuba diving, you won’t be looking at your phone. Nor will you have to make a mental effort     5     (get) away from the real world because physically, you already have! The underwater scenery provides the perfect place to calm your mind with     6     (peace) surroundings to admire.

Yoga lays stress on the control of breathing in and out, as breathing     7     (consider) the fundamental connection     8     body and mind. The number one rule of scuba diving is to breathe     9     (constant) and never hold your breath. A diver who is relaxed in body, breath, and mind becomes one with the water. It’s the supreme form of     10     (relax) when all you can hear is bubbles and the sound of your own breathing.

We always think it’s OK for us to leave our plants unattended during our vacation,but a recent study has led to a new     1    (discover).

Some scientists tested tobacco plants and tomato plants by cutting off their stems(茎)and     2    (stop)watering them.They then recorded their response with a microphone       3    (place)ten centimeters away.

They found that the plants began to scream ultrasonic(超声波)sounds, which they believed could convey their suffering     4     other plants.When the stem of a tomato plant was cut,the scientists found that     5     screamed 25 ultrasonic sounds of suffering within an hour.The tobacco plant that had its stem cut     6    (send)out 15.

The plants also seemed to respond to different     7    (stress)with the different intensities(强度)of sound.The scientists observed that the tobacco plants let out       8    (loud)sound when they were not watered than when they had their stems cut

The study answers the question     9    plants can feel pain or not.It can change the way that we think about the plant kingdom,which has been     10    (natural)considered to be almost silent.

The traditional Chinese lunar calendar divides the year into 24 solar terms. Awakening of Insects (惊蛰)     1       (fall) on Mar 6 and ends on Mar 20 this year.

Awakening of Insects signals a rise in temperature and increased rain fall. As the     2     (three) solar term in the lunar year,     3     (it) name suggests the fact that animals sleeping in winter are awakened     4     spring thunder and that the earth begins to come back to life. It is the key time for spring agricultural     5     (activity). It is also a good time for people to enjoy fun outdoors, especially for people living in the city.     6     (drive) to the suburbs, fishing in a lake or enjoying the singing bird will make for a perfect weekend in spring. The most popular fruit in this season is pears.

Eating pears around the Awakening of Insects     7     (be) a widely-practiced custom in China. As the weather gets     8     (warm) and the air becomes drier, people tend to feel their mouths and tongues are dry,     9     can cause colds or coughs. A pear is sweet, juicy and cold, moistening (湿润) the lungs to arrest a cough.     10    , pears are highly recommended during the Awakening of Insects.

A material can be really special when it was named after the place where it     1       (create)originally.That’certainly the case     2     “china”.And of all types of china，white porcelain(瓷)is among the most famous.

Nowadays，the     3     (tradition)material has taken on a modern look in the       4    (hand)of four Chinese artists in the Modern White Porcelain Exhibition.And the key word here is“modern”.One of the works     5     (be)a porcelain boat.But look     6     (attentive)and you’11 see that the boat     7     (build)with porcelain looks like a takeout box.Inside the boat is a statue of a baby.The baby stands for humans and the boat is       8     supports life.It suggests we may have done some damage to     9     environment and that we’re treating life like fast food.

All the four artists gave white porcelain a model style，each in     10     (they)own way.And this is what the exhibition’s theme comes from.It’s a dialogue between the past and the present.

10 . “I saw rice plants as tall as sorghum, each ear of rice as big as an ear of corn and each grain of rice as huge as a peanut. I could hide in     1     shade of the rice crops with a friend.” That is the dream of the     2     (agriculture) scientist Yuan Longping.

Yuan Longping, born     3     September 7, 1930, is known for developing the first hybrid rice varieties in the 1970s. Since then, hybrid rice     4     (grow) in over 20 countries,     5     (attract) attention from the whole world, especially areas at risk of hunger.

This year 88-year-old Yuan Longping has     6     (successful) developed rice growing in saltwater and desert. Though his rice could reduce food shortage, the new strain has a long way to go     7     it can be widely spread.

Yuan Longping’s achievement has brought him many awards and     8    (honor) both at home and abroad. As Yuan Longping accepted his Lifetime Achievement Award, he said that     9     lifetime achievement means is to achieve your dream with all your life.    10    , fame and wealth mean much less to him than his research, and he says he will focus on developing better rice.