（A） equivalent to the enrollment of
（B） the equivalent of those enrolled in
（C） equal to those who are enrolled in
（D） as many as the enrollment of
（E） as many as are enrolled in
12.A migraine typically afflicts one side of the head， lasts for hours or days， and may recur as infrequently as once every other month or often， as daily.
（A） as infrequently as once every other month or often， as
（B） as infrequently as once every other month or as often as
（C） infrequently， as often as once every other month， or often， like
（D） infrequently， like once every other month， or often， like
（E） infrequently， like once every other month， or as often as
13.Inflation has made many Americans reevaluate their assumptions about the future； they still expect to live better than their parents have， but not so well as they once thought they could.
（A） they still expect to live better than their parents have
（B） they still expect to live better than their parents did
（C） they still expect to live better than their parents had
（D） still expecting to live better than their parents had
（E） still expecting to live better than did their parents
14.The guiding principles of the tax plan released by the Treasury Department could have even a greater significance for the economy than the particulars of the plan
（A） even a greater significance for the economy than
（B） a significance that is even greater for the economy than
（C） even greater significance for the economy than have
（D） even greater significance for the economy than do
（E） a significance even greater for the economy than have
15.Once positioned in space， the Hubble Space Telescope will capture light from sources twenty times fainter compared to those that can be detected by ground-based instruments.
（A） compared to those that can be detected
（B） compared to those that can detect
（C） than that can be detected
（D） than those that can be detected
（E） than those detecting
