Section A

Directions: In this section, there is a passage with ten blanks. You are required to select one word for each blank from a list of choices given in a word bank following the passage. Read the passage through carefully before making your choices, Each choice in the bank is identified by a letter. Please mark the corresponding letter for each item on Answer Sheet 2 with a single line through the centre. You may not use any of the words in the bank more than once.

You might think of your teeth as tools, like built-in knives and forks, but if they are mere tools, why do they feel pain and wouldn’t it be better if they could just    26    under any condition? In spite of our    27    discomfort, it turns out there’s a good reason our teeth are so sensitive. Tooth pain is a    28    mechanism that ensures when a tooth is being damaged we’ll notice and do something about it.

If we eat something too hot or too cold, or if the tooth is worn down enough where the tissue    29    is exposed, all of those things cause pain, and then the pain causes the person not to use that tooth to try to protect it a little bit more. So it’s really a protective mechanism more than anything else. If teeth didn’t feel pain, we might    30    to use them in situations that damage them, and for humans, damaging    31    teeth is a problem because, unlike crocodiles, we can’t    32    them.

Teeth have three layers, only one of which-the innermost layer of the tooth-can hurt, as that layer of the tooth    33    both blood vessels and nerves. Pain is the only feeling to which the nerves in that layer respond. Whereas people with tooth sensitivity may complain, for example, of tooth pain    34    by heat or cold, the nerves in the inner layer don’t sense temperature. Rather, they feel pain, which may be    35    with, say, drinking something very cold.

A) adult   B) associated   C) chew   D) contains   E) continue   F) defense   G) dental   H) downward   I) emotional   J) implies   K) mammal   L) replace   M) swallow   N) triggered   O) underneath