--I would why he so strangely these days. --Recent pressure at study may account for his b

问题补充：

--I would why he so strangely these days.

--Recent pressure at study may account for his behavior.

A. was acting

B. is acting

C. acted

D. acts

答案：

A. was acting

(答案→)B. is acting

C. acted

D. acts

解析：考查时态。these days是与现在有关的时态，这几天他的情况，用is acting, 句意：——我想知道为什么这些天他表现地这么异常？——最近的工作压力可以说明他的行为的原因。