单选题 . ①Despite the extravagant colors of the flowers bees visit, until the early 1900s it was commonly thought that bees were entirely color-blind. ②To test this, zoologist Karl von Frisch set out an array of dishes on cards. ③The dish on one card, the only blue card among varying grays, contained sugar water. ④Once bees learned to visit this card and dish combination, he varied its position in the matrix. ⑤Next, he replaced all the cards and dishes with a new set of identical materials, only now leaving the blue card's dish empty. ⑥The bees nonetheless returned to the blue card. ⑦If their vision were monochromatic, they would likely have found at least some of the gray cards indistinguishable from the blue.

19. The author of the passage refers to "extravagant colors" primarily to ______

A、 validate a view about bees' color vision that was once commonly accepted
B、 suggest why it might be surprising that bees were thought to be color-blind
C、 complicate the debate about bees' color vision
D、 point out a reason for bees' visual limitations
E、 anticipate an objection to the methodology of the experiment described in the passage

【正确答案】 B

【答案解析】 B：本题是功能题，但问的是让步部分的功能，因此有两种思路：a. 承认一个观点在某种程度上是正确的；b. 衬托转折之后的内容。本题的这一让步部分没有针对一个观点发表评价，因此不是第一种功能，所以正确选项的选择方向是衬托转折之后的内容，因此选项B正确。
A：a view对应老观点，即蜜蜂是色盲。本句是由despite连接的让步转折，因此extravagant colors和后面的老观点在逻辑上是取反的，但是本选项的validate(证实)对应的是取同的关系，逻辑不对。
C：文章没有针对蜜蜂的色觉进行争论，所谓争论，指的是两个相反的观点同时存在，不分上下，难分对错。但是文中提到在20世纪早期，大家普遍认为蜜蜂是色盲，之后的实验反驳了这一观点，所以文章不存在争论。
D：该项错误原因同选项A， “原因”也是前后取同的逻辑。
E：an objection无对应。