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2013 ‫מועד אוקטובר‬ - 49 - ‫ פרק שני‬- ‫ אנגלית‬

Text II (Questions 18-22)

(1) For thousands of years, people traveling through the desert heard mysterious noises
that they believed were made by ghosts or demons. Marco Polo, the 13th-century Italian
explorer, reported that "evil spirits at times fill the desert air with the sounds of drums
and the clash of arms." Today, scientists have a much less fantastical explanation: those

(5) frightening noises are a purely physical phenomenon, created by the desert sand.

At least thirty "booming" sand dunes have been found in Africa, Asia and North
America. These booming dunes are distinct from other types of sand that make noise.
Walking on some beach sand, for example, produces relatively undramatic squeaking
sounds underfoot. This type of sand, called "squeaking" or "whistling," can be found

(10) along lakes and seashores throughout the world. Booming sand, by contrast, occurs
almost exclusively in large, isolated dunes deep in the desert, far from water.

What, precisely, causes the phenomenon of booming sand? Is it the size or shape of
the individual grains of sand? The way in which they interact? Unfortunately, research
on booming sand has been hindered by the rarity of the phenomenon and the difficulty

(15) of reproducing sand "booms" in laboratories. In addition, because early research did
not differentiate clearly between booming and squeaking sand, much of it is unreliable.
Consequently, though booming dunes are no longer considered frightening, they remain
mysterious.

Questions

18. Marco Polo is mentioned in the first paragraph because he -

(1) provided an early description of what is now known as booming sand
(2) presented a less fantastical explanation of booming sand
(3) was the first person to hear booming sand
(4) believed that ghosts and demons caused sand to make booming noises

)‫© כל הזכויות שמורות למרכז ארצי לבחינות ולהערכה (ע"ר‬

.‫ בלא אישור בכתב מהמרכז הארצי לבחינות ולהערכה‬- ‫ כולה או חלקים ממנה‬- ‫ או ללמדה‬,‫אין להעתיק או להפיץ בחינה זו או קטעים ממנה בכל צורה ובכל אמצעי‬