The most important thing about cotton in history is _____ part that it played in ____ Industrial Revolution.
. ______we’ll be able to drive a car______ by electricity, solar energy in about ten years.
. The chickens will provide us _______ feathers, ______ we can make use for cleaning the table and benches.
. --- This book by Tony Garrison is of great use for our course. --- But I think his latest one is______ worth reading.
. --- My son is addicted to drugs. He isn’t hopeless, is he?--- Yes, ______ he mends his way and starts all over.
. The ancient Chinese vases _______ display attracted lots of experts and collectors, some of whom suggested they______ on the next fair.