It remains to be seen ________ the newly formed committee's policy can be put into practice.
Believe it or not, he was seen ______upstairs just now.
They knew her very well. They had seen her ____up from childhood.
Mrs. Smith warned her husband _____after drinking again and again.
The first textbooks _____for teaching English as a foreign language came out in the 16th century.
There was a terrible noise _______the sudden burst of light.