填空题

Directions: In this section, you will hear a passage three times. When the passage is read for the first time, you should listen carefully for its general idea. When the passage is read for the second time, you are required to fill in the blanks numbered from 36 to 43 with the exact words you have just heard. For blanks numbered from 44 to 46 you are required to fill in the missing information. For these blanks, you can either use the exact words you have just heard or write down the main points in your own words. Finally, when the passage is read for the third time, you should check what you have written.
A man steps on what seems like solid ground but discovers with horror that the ground is giving way beneath his feet. The man struggles (36) , but he is mercilessly (37) He cannot escape. Slowly he sinks deeper and deeper until at last he is gone, (38) in the treacherous earth. The solid ground was solid only in (39) It was actually quicksand, which is a deep (40) of fine sand mixed with water.
How is quicksand formed Water pushes up from below the surface and is held by the sand. The (41) of sand are forced apart by the water. They cannot hold any weight. The subsurface water may have come from a spring, a river, or a stream. Sometimes pools of water near beaches become filled with sand. When the soil under these pools does not allow for good drainage, the sand can become (42) of quicksand.
Is it true that a man who steps into quicksand is (43) to die No, four men have fought their way from quicksand to firm land again. (44) . Quick movements will make the sand yield temporarily, but then it rushes and settles solidly around the body.
(45) . When the weight of the sand his body has displaced equals his weight, he will stop sinking. With feet held still, and slow movements of arms, (46) .