1 . Salad seeds (生菜种子) that went on a round trip to outer space and back grew at a slightly slower rate than the ones on earth, scientists found, thanks to thousands of young people who helped conduct an out-of-this-world experiment.

The project started in 2015, when British astronaut Tim Peake took a million seeds with him on his journey to the International Space Station (ISS). The seeds spent six months there before they were sent back to Earth in 2016. In a message sent from the ISS, Peake said the purpose of the science experiment was to find out if the conditions in space affected the seeds’ ability to grow.

Around 600,000 pupils at 8,600 schools in the UK were then asked to grow the rocket seeds that had been to space, along with regular seeds that had never left the planet. Peake described the experiment as “one of the largest and most inspirational experiments of its kind”.

The results of the study, which have just been published, found that the space seeds grew more slowly than the ones that had stayed on Earth. Researchers on the experiment said this was due to the stresses of space travel, such as the zero-gravity (零重力) atmosphere and high levels of cosmic rays (宇宙射线), which slowed the growth of the plants.

Now researchers are hopeful that if the seeds are properly protected, it might be possible to grow plants during future space tasks to other planets. Dr Jake Chandler, from University of London, who led the study, said, “The possibility of eating home-grown salad on Mars may be one small step closer.”

1. Why did Tim Peake take seeds to ISS?

A．To explore the secret to gravity.

B．To have astronauts grow salad in ISS.

C．To promote young kids’ interest in salad.

D．To test the space’s influence on seeds’ growth.

2. How did Tim Peake feel about the experiment?

A．Encouraged.

B．Disappointed.

C．Confused.

D．Concerned.

3. From which part of a website is the text probably taken?

A．Health.

B．Science.

C．Education.

D．Business.

4. What could be the best title of the text?

A．Space study, a hot topic

B．Salad growing, a hit among students

C．The conditions in space affect the seeds’ growth

D．Man’s exploration to Mars, a big step forward

2 . 语法填空

Today, much of the world’s ocean is still a mystery.Only 5 percent of it     1     (explore) so far. In fact, we know more about some areas of Mars     2     some parts of the world's ocean.

New technology, however, is helping scientists explore these     3     (hide) worlds. For example, scientists are using an underwater vehicle called DeepSee to explore seamounts — underwater mountains. Scientists have used DeepSee to study Las Gemelas, an area of seamounts near Costa Rica. A huge variety     4     species live around Las Gemelas. Some of these species may have chemicals     5    — can help people fight illnesses.

The     6     (deep) location of the earth is the Mariana Trench in the Pacific Ocean. The ocean floor there is about 11,000 meters deep. In 2012, filmmaker and explorer James Cameron     7     (reach) the Mariana Trench in a vehicle called Deepsea Challenger. He was the first     8     (complete) the journey alone. Cameron took     9     (photo) and made videos on the ocean floor. Deep-sea exploration also helps us in other ways. For example, we are learning how underwater earthquakes cause tsunamis(海啸).As Cameron says, “This is the beginning of     10     (open) up a new frontier.

3 . 阅读下面材料，在空白处填入适当的内容（1个单词）或括号内单词的正确形式。将答案填写在答题卡的相应位置。

Scientists have discovered that     1     (stay) in the cold could help us lose weight.Researchers at the University of California found that exposure to the cold increases levels of a protein that helps form brown fat — the type of fat that produces heat and keeps us warm.Brown fat burns energy,     2     helps us lose weight.White fat stores extra energy, which results     3     weight gain.

The researchers said that because air conditioning and heating give us constant,     4     (comfort) temperatures, our body’s need for brown fat has decreased.They found that: “Outdoor workers in northern Finland who     5     (expose) to cold temperature have a significant amount of brown fat when     6     (compare) to sameaged indoor workers.”

The research was conducted on two different control groups of mice.    7     group was injected with the protein that helps create brown fat.This group later gained 30% less weight after both groups were fed highfat diets.The researchers say this could be good news in the fight against obesity.People who are obese have     8     (low) levels of brown fat than thinner people.Head researcher Hei Sook Sul said, “This protein could become an important target for research into the treatment and     9     (prevent) of obesity and obesityrelated diseases.” She added, “If you can somehow increase levels of this protein, you could     10     (possible) lose more weight even if eating the same amount of food.”