21. To many teenagers the cellphone is not only _____useful tool but also ____ way to have fun and be cool.
These two buildings are similar to each other in many _____ .
What is the _____ of this telescope? A. wayB, distance C. length D. range
Grain output _____ greatly in the past few years.
I can't _____ her another day; she never stops complaining.
He has by chance _____ the answer to that problem.