Surfing the Internet is ___ a kind of relaxation, ____ our knowledge.
_____ his knowledge of the mountainous country, John Smith was appointed as our guide.
Between the two roads ________ a TV tower called“Skyscraper Tower”.
.Nothing but one desk and six chairs ________ in the room.
“If anybody ________,please put down ________ name,”said the teacher to the monitor.
The secretary and principal ________ at the meeting now.