When a leafy plant is under attack, it doesn’t sit quietly. It is reported     1     maple trees being bitten by insects send out a particular smell that neighboring plants can get. These chemicals     2     (call) VOCs come from the injured parts of the plant and seem to be an alarm.

Scientists have found that all kinds of plants give out VOCs when they     3     (attack). It’s a plant’s way of crying out. But does anyone listen? They     4     (obvious) do. Some pump out smelly chemicals to keep insects away. But others pump out perfumes     5     (attract) different insects.     6     their arriving, the attackers get attacked. Those     7     were lunching become lunch now.

In study after study, it appears that these chemical conversations helped the     8     (neighbor) because they heard the alarm and knew what to do.

Does this mean that plants talk to each other? Scientists don’t know. Charles Darwin, over 150 years ago, imagined a world far     9     (busy), noisier and more intimate(亲密的)than the world we can see and hear. However, our senses are     10     weak to know that there’s a whole lot going on.

【推荐2】Your teeth may be part of your smile,_______they have a more important job—they are the first step in the process of digestion. You have three _________(kind) of teeth. In the very front of your mouth are eight flat, thin teeth called incisors. They are used for cutting and biting food. Next to these are pointed teeth called canines, _________ also help you tear food. The remaining teeth are molars. These teeth have flat tops for crushing and grinding the food.

“Failing to open curtains fully makes people more likely to get sick”,     1     new study suggests. It found sunlight kills disease-causing bacteria     2     live in dust, while darker conditions let them thrive (繁殖). The findings     3     (publish) in the journal Microbiome.

Researchers     4     (warn) the problem also affects windowless offices. Study leader Dr. Ashkaan Fahimipour said: “Humans spend most of their time indoors, where dust carries bacteria     5     ( make) us sick.

“Therefore, it’s important     6     (understand) how the buildings we live influence dust eco-systems and how this could     7     (serious) affect our health.”

His team at the University of Oregon chose 11 small rooms and allowed in     8     (differ) levels of sunlight. After 90 days, dark rooms had double the number of bacteria able to reproduce. Fahimipour added: “We hope that with     9     (far) understanding we can design access to daylight in     10     (build) schools, offices, hospitals and homes in ways that reduce the risk of dust-borne infections.”