专找野草的农田“小卫士”
Weeds (野草) are wild plants. They grow in fields. Farmers do not like them in their fields. So they use farm chemicals (农药) to kill them. But chemicals are bad for nature.
Most farming machines are big and expensive, so farmers do not use them very often. They leave a lot of chemicals in the land. It is very bad.
Now some AI drones (无人机) can help farmers. The drones fly over the fields. They find weeds and put chemicals only on them. Farmers spend less money. It is also good for the Earth.
1.1. Where do weeds grow?
A In fields.
B In parks.
C In rivers.
D
解析：选A。A 细节理解题。原文第一段明确提到 “They grow in fields.”，即野草生长在田地里，因此A项 “In fields.” 正确。B“在公园里”和C“在河里”文中均未提及。故选A。
2.2. Why don’t farmers use big machines often?
A They are bad for nature.
B They are big and expensive.
C They leave many chemicals.
D
解析：选B。B 细节理解题。原文第二段明确提到 “Most farming machines are big and expensive, so farmers do not use them very often.”，即大多数农机又大又贵，所以农民不常使用，因此B项正确。A“对自然有害”原文说的是农药（chemicals）对自然不好，不是大机器；C“留下大量农药”是文中提到的后果，但不是题干所问“不经常使用”的直接原因。故选B。
3.3. What do AI drones find in fields?
A Crops.
B Weeds.
C Birds.
D
解析：选B。B 细节理解题。原文第三段明确提到 “They find weeds and put chemicals only on them.”，即AI无人机在田里发现野草并只对野草施药，因此B项正确。A“庄稼”和C“鸟”文中没有说无人机寻找它们。故选B。
4.4. What is the main idea of the passage?
A Chemicals are bad for nature.
B Farmers spend money on big machines.
C AI drones help farmers.
D
解析：选C。C 主旨大意题。全文先说明野草和农药的问题、大机器成本高且带来农药残留，最后引出 “Now some AI drones can help farmers.”，并说明无人机只对野草施药、省钱环保，因此文章主旨是AI无人机帮助农民，C项正确。A“农药对自然有害”和B“农民花钱买机器”只是文中局部细节，不能概括全文。故选C。