Pesticides might just be a bee's. worst enemy. They harm their brains, stow down their re-production, and even kill their buzz. Now it seems they damage their social lives and reduce their ability to care for their young.

While previous studies have shown that commonly used neonicotinoid pesticides make bees sick and affect how they search for food and navigate, a new study gives more of an idea of how these chemicals affect the internal workings of a colony. Studying these effects has proved difficult, so the team employed a new technique. They stuck tiny QR codes to the backs of bumble-bees and tracked their movements using a robotic camera.

The researchers looked at 12 colonies housed in a lab, giving some the same level of imidacloprid-the world's most commonly used pesticide-that they'd be exposed to in the wild while keeping others pesticide free as controls. They checked on them for a few minutes 12 times a day. The findings are published in the journal Science.

Unfortunately, the researchers found a number of obvious differences between the bees exposed to the pesticide and the controls. The bees given neonicotinoids spent less time interacting with other bees and more time resting. This lull (间歇) in activity tended to happen more at night, but the researchers aren't sure why.

“Bees actually have a very strong circadian rhythm (生理节奏),”lead author James Crall explained in a statement. “So what we found was that, during the day, there was no statistically observable effect, but at night, we could see that they were crashing. We don't know yet whether the pesticides are destroying circadian gene regulation or if this is just some, maybe physiological feedback..But it suggests that, just from a practical perspective, if we want to understand or study these compounds, looking at effects overnight matters a lot."

【小题1】How was the research conducted?

A．By performing a survey.

B．By collecting information.

C．By asking questions.

D．By making comparisons.

【小题2】What does the underlined word“controls" in Paragraph 3 refer to?

A．The tools used to observe the bees.

B．The bees without being exposed to the pesticide.

C．The researchers taking charge of the experiments.

D．The data recorded by the robotic camera.

【小题3】What happened to the bees exposed to the pesticide at night?

A．They forgot to feed the young.

B．They preferred communicating more.

C．They lost the ability to rest.

D．They remained less active.

【小题4】What's the purpose of the passage?

A．To call for the toughest ban on the chemicals.

B．To check the best time to observe experimental results.

C．To inform people of the worrying effects of pesticides.

D．To recommend measures to improve the quality of pesticides.