B. Fill in the blanks with the appropriate form of the verb or verb phrase given:
[填空题]
(1) Primary distillation, which yields several fractions, ______ (carry) out in the main column of the crude distillation unit.
[填空题]
(2) It is time we ______ (think) about drawing up a detailed plan for the project.
[填空题]
(3) Halloween was originally a religious holiday, but its religious character _________ (lose) in the United States, and now it is celebrated mostly as a children's day.
[填空题]
(4) When ______(question) the boy, the policeman felt a little sorry for him.
[填空题]
(5) Three years later, _____ (realize) that he was not as well prepared as he should be,either materially or psychologically, Mackenzie returned to Britain to get ready for his next journey.