In the experiment we kept a watchful eye the developments and recorded every detail. A.

发布时间：2020-08-14 23:58:42

In the experiment we kept a watchful eye      the developments and recorded every detail.
A. in
B. at
C. for
D. on

网友回答

A. in
B. at
C. for
(答案→)D. on
解析：因为keep an eye on…是习语，意为“密切注视…”。
以上问题属网友观点，不代表本站立场，仅供参考！