－ What does the sign over there read － “No person ________ smoke or carry a lighted cigarette, cigar or pipe in this area”

1_____education is the instruction that occurs when the instructor and students are separated by distance or time,or both

计算机主机主要由______组成。

计算机的主机由______部件组成。

____组成计算机主机。

微型计算机主机由____组成。

Either he or I ______to the airport.

Duty is an act or a course of action that people __________you to take by social customs, law or religion.

Duty is an act or a course of action that people ______you to take by social customs, law or religion.

Project ______is an uncertain event or condition that，if it occurs，has a positive or a negative effect on at least one project objective，such as time，cost，scope，or quality．

It will be a relief over the death of a friend or a relative if the friend or relative dies from ______.

Hurry up, or you ______ catch the train.