Some people are living very long lives. What are some of their secrets to longevity?     1    (eat) the right food plays a big role. Exercise is also important. A study found that people who exercised at     2    (recommend) levels gained 3-4 years of life compared to those     3     were inactive. In addition, there is also a link between happiness and lifespan — happy people with a positive outlook on life tend to live     4    (long) and experience better health than their unhappy peers.

Yuan Longping realised that larger fields were not the solution. Instead, farmers needed to boost yields in the fields they had. How this could be done was a     1     (challenge) question at the time. Yuan was convinced that the answer could be found in the creation of hybrid rice. One characteristic of hybrids is     2     they usually attain a higher yield than conventional crops. However,     3     it was possible to develop a hybrid of self-pollinating plants such as rice was a matter of great debate.

Roald Amundsen,     1    (bear) in 1872 near Oslo, Norway, left his mark on the Heroic Era as one of the most successful polar explorers in the world. He became the first to travel through the Northwest Passage, in his ship Gjoa in 1903-1906. After this journey, plans     2    (make) to reach the North Pole, but news of Peary’s success in reaching the pole arrived,     3    caused Amundsen to make new plans for a journey to the Antarctic and the South Pole. On December 14, 1911, Amundsen and four others     4    (stand) at the South Pole, a month before Robert Scott.

Going from junior high school to senior high school is a really big challenge. The first week was a little     1     (confuse). First, I had to think very carefully about which courses I wanted to take. The school adviser helped me choose the suitable ones: maths, English, chemistry, world history, and Chinese. I know that Chinese is a very difficult language,     2     I hope to be fluent when I graduate. My adviser recommended that I should sign up for advanced literature     3     I like English and I’m good at it.