下面的短文后有2项测试任务： (1)第23-26题要求从所给的6个选项中为第1-4段每段选择1个最佳标题； (2)第27-30题要求从所给的6个选项中为每个句子确定1个最佳选项。 Icebergs 1
Icebergs are among nature’s most spectacular(壮观的) creations, and yet most
people have never seen one. A vague air of mystery envelops them. They come into
being—somewhere—in faraway, frigid waters, amid thunderous noise and splashing
turbulence, which in most case no one hears or sees. They exist only a short
time and then slowly waste away(消融) just as unnoticed. 2
Objects of sheerest(最纯粹的) beauty they have been called. Appearing in an
endless variety of shapes, they may be dazzlingly white, or they may be glassy
blue, green or purple, tinted faintly or in darker hues. They are graceful,
stately, inspiring—in calm, sunlight seas. 3 But they are
also called frightening and dangerous, and that they are—in the night, in the
fog, and in storms. Even in clear weather one is wise to stay a safe distance
away from them. Most of their bulk is hidden below the water, so their
underwater parts may extend out far beyond the visible top. Also, they may roll
over unexpectedly, churning the waters around them. 4
Icebergs are parts of glaciers that break off, drift into the water, float
about awhile, and finally melt. Icebergs afloat today are made of snowflakes
that have fallen over long ages of time. They embody snows that drifted down
hundreds, or many thousands, or in some cases maybe a million years ago. The
snows fell in polar regions and on cold mountains, where they melted only a
little or not at all, and so collected to great depths over the years and
centuries. As each year’s snow accumulation lay on the surface, evaporation and
melting caused the snowflakes slowly to lose their feathery points and become
tiny grains of ice. When new snow fell on top of the old, it too turned to icy
grains. So blankets of snow and ice grains mounted layer upon layer and were of
such great thickness that the weight of the upper layers compressed the lower
ones. With time and pressure from above, the many small ice grains joined and
changed to larger crystals, and eventually the deeper crystals merged into a
solid mass of ice. A．Formation of Iceberg B．Iceberg Is
Beautiful C．Color of Iceberg D．Iceberg Is Dangerous E. Iceberg Is
Mysterious F. Classification of Iceberg Paragraph 1 ______