(Para 1) Rats and other animals need to be highly attuned to social signals from others so they can identify friends to cooperate with and enemies to avoid. To find out if this extends to non-living beings, Laleh Quinn at the University of California, San Diego, and her colleagues tested whether rats can detect social signals from robotic rats.
Quinn and her colleagues conducted a test to see if rats can ______.
[A] pick up social signals from non-living rats
[B] distinguish a friendly rat from a hostile one
[C] attain sociable traits through special training
[D] send out warning messages to their fellows
Homework has never been terribly popular with students and even many parents, but in recent years it has been particularly scorned. School districts across the country, most recently Los Angeles Unified, are revising their thinking on this educational ritual. ①Unfortunately, L.A. Unified has produced an inflexible policy which mandates that with the exception of some advanced courses, homework may no longer count for more than 10% of a student’s academic grade.
②This rule is meant to address the difficulty that students from impoverished or chaotic homes might have in completing their homework. But the policy is unclear and contradictory. Certainly, no homework should be assigned that students cannot complete on their own or that they cannot do without expensive equipment. But if the district is essentially giving a pass to students who do not do their homework because of complicated family lives, it is going riskily close to the implication that standards need to be lowered for poor children.
L.A. Unified has made the rule about homework mainly because poor students ______.
[A] tend to have moderate expectations for their education
[B] have asked for a different educational standard
[C] may have problems finishing their homework
[D] have voiced their complaints about homework