__________ to smart phones just before bed, as a research says recently, can lead to poor night’s sleep.

lumbia has finished the task in theInternational Space Station and is reported to come back to the earth tomorrow,or to be more _____ , at 3:32p.m. local time.

We must behave ____ at a formal table.

In order to help the police ，the witness described what he had seenvery carefully not to ______ any detail.

Theteachercameupwithanideatostoptheboyfromplayingcomputergamesallday