People may use the expression"birdbrain"in English to talk about someone who is stupid,but crows prove that this is unfair.Now it has been discovered that crows may understand analogies  . It was once thought that only humans could understand analogies,which help us to solve problems creatively,put things into categories,and make scientific discoveries. To test this ability in animals,scientists do"relational matching-to-sample"(RMTS) tests,according to the IFL Science website.If a pair was AA,for example,then picking BB to match it would be correct.If the pair was CD,however,then EF would be correct. Apes and monkeys have learned RMTS,but scientists wanted to know if crows could do it,too.An international team led by Edward Wasserman from the University of Iowa in the US first trained two hooded crows to match things by color1,shape,and number in what is called"identity matching-to-sample(IMTS)",then moved onto RMTS. For the IMTS test,the birds were put in a cage with a plastic tray that had three cards and two cups in it.The card in the middle was the sample card.The cups on either side were covered with the other two cards:One was the same as the sample (in the color1,shape,or number of shapes pictured),while the other wasn't.The cup with the card that matched the sample card contained two wormsto eat. In the second part of the experiment,the birds were tested with relational matching pairs.A card with two same-sized circles,for example,meant they should pick the test card with two same-sized squares and not two different-sized circles.The birds did well in the more difficult test and picked the correct card more than three quarters of the time,Science News reports. Wasserman was surprised that crows were able to solve the problem without any training in RMTS."What the crows have done is extraordinary,"he said in a news release."Honestly,if it was only by force that the crows showed this learning,then it would have been an impressive result.But this was  spontaneous." So perhaps it's time to stop saying"birdbrain"permanently! Which of the following is TRUE about the tests on the hooded crows?
The birds did better in RMTS than in IMTS. The birds were first made to do RMTS,then IMTS. The birds picked almost all the correct cards in RMTS. In the IMTS test,the birds needed to identify the sample card to get rewards.