They studied hard although _____ .
  A) they were tired
  B) they were good friends
  C) they were happy
  D) they had a lot to eat

  He began to realize that he _____ mistake.
  A) is making
  B) has made
  C) had made
  D) will make

  They were speaking so loudly that I couldn't help _____ what they
  said.
  A) to overhear
  B) overhearing
  C) overhear
  D) but to overhear

  We now insist that all cars _____ seat belts to reduce the death toll.
  A) to have
  B) will have
  C) have had
  D) have

  His wife, _____ lives in Paris, is a fashion model.
  A) who
  B) that
  C) whom
  D) whose

  It is necessary that everyone _____ here on time.
  A) will be
  B) be
  C) are
  D) to be

  _____ is that there is a risk of heart attack for the elderly.
  A) One important drawback of aerobics
  B) There is one important drawback of aerobics
  C) It is one important drawback of aerobics
  D) If there is one important drawback of aerobics.

  The factory _____ he works is closing down.
  A) that
  B) which
  C) where
  D) whom

  His doctor recommended that he _____ taking sleeping pills for a
  while.
  A) would try
  B) should try
  C) tries
  D) tried

  I recommended that the patient _____ on as soon as possible.
  A) is operated
  B) operated
  C) would be operated
  D) be operated