问题
选择题
In the experiment you should keep a watchful eye ______ the developments and record every detail.
A.in
B.at
C.for
D.on
答案
答案:D
keep an eye on sth 注意,监视
In the experiment you should keep a watchful eye ______ the developments and record every detail.
A.in
B.at
C.for
D.on
答案:D
keep an eye on sth 注意,监视