He asked me _____ finished my work.
The teachers hope students can keep a ________ between work and relaxation.
I'll be busy on ________ Sunday morning, and perhaps I'll have ________ late night.
It is high time that we started to consider what ________ we should take to reduce heavy smog caused by traffic fumes and other pollutions.
________ walk is expected to last all day, so bring ________ packed lunch.
In recent years, many mainland residents have rushed to Hong Kong to buy baby milk powder due to their ________ about its quality.