He lost his favorite watch, _________ made him very sad.
A. that B. it C. which D. as
Mary has a house _________ as Tom's.
A. twice as big B. as twice big
C. big as twice D. twice bigger
Professor Li is the person to ____________ you should write.
A. whom B. who C. which D. whose
Do you know the reason _______ he was late?
A. that B. which C. where D. why
I’ll take you to the museum ______ you may see everything _________ you want.
A. which; that B. where; that
C. in which; which D. where; what
Is oxygen the only gas ________ helps fire burn?
A. that B. / C. what D. it
