Nina has run marathons in 32 countries. All of her runs have a guiding purpose: to call attention     1     global water issues. Nina recently finished her year-long series of runs in Chicago,     2     thousands were attending a water conference.She called for action     3    (address)the struggles of people around the world     4    (face) “too little water or too dirty water”. Her efforts have encouraged others to take part by running through a global campaign called“Run Blue”.

Mangroves, known as “red forest” in China, grow between land and sea, characterised by their complex roots. When     1    (see) from afar, the mangrove forests appear more splendid.

Mangroves can help soften waves and protect     2    (city) from coastal winds. For these reasons, they are praised as “coastal guardians”. Up to now, China     3    (establish) a number of protected areas with mangroves.

Every culture is riddled with unwritten rules, such as ones on punctuality (守时). I’m British. Soon after moving to Switzerland, I     1    (throw) a house-warming party and was greatly surprised when all 30 guests showed up     2    (exact) on time. Years later, having moved to France. I turned up at the appointed hour for a dinner, only to find that no other guest    3    (arrive) and my hostess was still in her sleeping suit.

Since people can’t always eat out or cook for     1     (they), they get takeout or order delivery. More takeout and more food delivery equal more waste, especially plastic waste. That includes cups, bottles, and bags, most of     2     are only good for one use. That’s a big problem and it is getting even     3     (bad). The use of those plastics     4     (increase) by 300% since 2019. The world won’t survive if this situation continues.

Why do humans prefer some smells over others? One theory, increasingly     1       (support) by experts, suggests that smell preferences are learned. It’s easy to explain how we determine     2     smells are dangerous or not: we learn. This has been adopted to ensure easier detection of gas leaks. Gas naturally     3     (have) no recognisable smell. However, a strong smell is added so that we can raise the alarm when we detect the smell associated with danger.

Helen was walking down the street late     1     the evening, her arms filled with grocery bags. Focused on balancing the bags, she didn’t notice her wallet falling out of her pocket. As Helen walked on, she heard a man charging towards her. Fearful that he might have an intention     2     (harm) her, Helen started to run. Eventually, the man     3     (catch) up with her, and he was only trying to return her wallet!

There     1    (be) a dramatic rise in the number of extreme weather events over the past 20 years,    2    (cause) largely by rising global temperatures,according to a new report from the United Nations. From 2000 to 2019, there were 7,348 major natural disasters around the world,    3    (result) in USD 2,970 billion in economic loss．Much of this increase can be due to climate change. The findings show a critical need     4     (invest) in disaster prevention.

Sam is an in-real-life streamer（播主），and he live streams himself just going about his day．While riding his bike home     1     a cold night，he came across a sad-looking elderly woman wandering the streets by herself．The poor woman wasn't able to give him any information about     2     she lived．Sam walked her to a nearby convenience store so that she could     3    （safe） wait for the police to take her home．

Why do we dream？Scientists aren't completely sure,and they have diverse    1     (idea)．Dreams might be a side effect of memory making.When you sleep,your brain sorts through everything     2     happened during the day，trying to link new experiences to old memories.As it     3     (connect) things，your brain turns them into a story,and you get a dream．