D(2026·江苏徐州)跨生物—叶蜂
If you are a biology fan, you might be interested in sawflies.
When a sawfly lays eggs, she must cut into a plant without killing it. Her cuts are careful and exact. She needs to make sure the plant stays alive to feed her larvae(幼虫).
How does she manage to do that? Scientists discovered the sawfly uses a special ovipositor(产卵器). It works like a small saw(锯) that seems to "think for itself", and this saw has two blades like cutting teeth. They move against each other smartly.
They cut the soft part of plants but avoid the stronger tubes(管), as these tubes should carry water and nutrients(营养) for her larvae. Different sawflies even have different tooth shapes that match the plants they usually cut into. "There are no computers, but it has become perfect over millions of years," said a scientist.
To test if this can help humans, scientists made a model of the sawfly's cutting tool more than 400 times and tried it on man-made human tissue(组织). The tool cut soft materials well without hurting stronger tissues. This could be useful for surgeons who do operations in areas where it's hard to see clearly, and must not hurt important tissues.
Scientists believe this discovery could help make a new kind of medical tool that is simple, safe and exact. And there are more than 8,000 kinds of sawflies, each with its own special design. This may be just a start. Nature may have many surprises waiting for you.
()12. A female sawfly cuts a plant carefully to .
A. mark the plant for other sawflies
B. keep the plant alive for her larvae
C. get food for herself while laying eggs
D. gather plant parts for building a nest
()13. Which is NOT a function of a female sawfly's ovipositor?
A. Its cutting teeth move against each other smartly.
B. It cuts soft plant tissue while leaving stronger parts alone.
C. It cuts the plant tissue and carries water and nutrients.
D. Its cutting teeth are shaped to match the plants they cut into.
()14. If surgeons use a sawfly-style tool, which part of the body would it avoid cutting?
A. Fat.
B. Skin.
C. Blood vessels.
D. Bones.
()15. In the last paragraph, why does the author mention that there are over 8,000 kinds of sawflies?
A. To show there are too many sawflies to study.
B. To show each kind of sawfly might give us a different idea.
C. To show all sawflies have the same cutting tools.
D. To show the number of sawflies is bigger than that of other insects.