Since we have a focused subject,we should not talk____

问题描述:

Since we have a focused subject,we should not talk____
A.at once b.at hand c.at intervals d.at random

因为我们要专心于这项工作,所以我们不应该现在说话
a立刻
b在手
c间隔
d随机
我觉得b更贴切些吧~at hand 可以理解为现在的意思