2012年大学英语六级考试考前预测卷（第三套）_第5页

57. What happened when Earth's last ice agewas getting started?
A) Water began to be trapped in glaciers.
B) Glaciers began to melt into water.
C) Sea levels suddenly rose.
D) Sea levels suddenly dropped.
58. It's believed that for the past severalhundred thousand years, each ice age would last an average of_______ years.
A) 100,000
B) 90,000
C) 70,000
D) 11,000
59. What does "the puzzle" (Line1, Para. 4) refer to?
A) The cause of the ice-age cycle.
B) The duration of an ice-age cycle.
C) Whether the ice-age cycle is related tothe changes in Earth's orbit.
D) How fast the seas rose when the ice-agecycle was about to start.
60. What happened when the glaciers weremelting at a tremendous rate?
A) The mid-latitudes were flooded first.
B) The climate lost its regular balance.
C) The ice age almost came to an end.
D) The sea level rose rather quickly.
61. According to Daniel Muhs, data takenfrom Barbados and New Guinea suggested that the sea level _______.
A) remained unchanged
B) didn't rise much
C) rose remarkably fast
D) rose mysteriously