Most of the Chinese people are big savers — they get used to putting every penny in the bank ______ a rainy day.
Many people complained about the stones scattering on a roadway, but ______ did anything about getting the stone out of the way.
Recently, much more emphasis has been put ______ developing the students’ creativity.
“Simpler” books are the foundation ______ students build a lifelong habit of reading and further the actual skill of reading for longer and stronger periods of time.
After a long and tiring flight, Mr. Ritz was frustrated at the news ______ his luggage had been sent to Hong Kong by mistake.
In the past twelve months the research members ______ the effectiveness of many materials in a home building.