黄皮第1篇第2题，及首句意思

vivianwsp198

2.      The passage suggests that Jarvis's work has called into question which of the following explanatory variables for naked mole rat behavior?

(A)Size

(B)Age

(C)Reproductive status

(D)Rate of growth

(E)Previously exhibited behavior

 

Inference

The fact that an inference must be made is indicated by the word suggests in the question. What does the passage say about Jarvis's work? It is mentioned in just one sentence in the passage (lines 33-35); Jarvis posits that growth rate may affect how long any individual rat performs a task, regardless of its age. Thus, it can be inferred that the variable that Jarvis^'s work calls into question is age.

A       Jarvis's work discusses rate of growth rather than size.

B        Correct. Jarvis^'s work tends to discount age

as a determining factor in rat behavior.

C       Reproductive status is not mentioned in

connection to Jarvis's work.

D      Rate of growth is the factor that determines

what tasks the rats do and for how long.

E       Previously exhibited behavior is not discussed

in the context of Jarvis^'s work.

The correct answer is B.

红色字体我老想不通，虽然看了答案也能猜出点意思，但还是觉得有点怪，哪位详细解释下，尤其是explanatory variables ，翻译为：解释性/说明性变数？

因为不能好好理解题目问的什么就没法最对题目了

Until recently, scientists did not know of a close vertebrate analogue to the extreme form of altruism observerd in eusocial insects like ants and bees.

这句话怎么翻译，尤其是红体字