How to succeed in cloze tests? - grammar forms, word formation, vocabulary


Note the grammar form of the clue expressions, especially those ending with –s. Can they be both
nouns and verbs? Are any of them evidently only nouns or only verbs?

Clue: Affected   bubbles   chipped   expands   occurring   patches   properties   releases
through   undergone   weaken

a/ only nouns:

b/ only verbs:


Compare the similar ending undergone and weaken.  What grammar forms are they?


What grammar forms can follow the verb be?


Is there a preposition in the clue? If so, find its occurrence in the following text.


Clue: Affected   bubbles   chipped   expands   occurring   patches   properties   releases
through   undergone   weaken (Use one of the words twice.)


Chemical weathering

There is a kind of weathering that does not change only the size of the rock material, but changes
the material itself. You have most likely seen   1…………..   of rust on a bicycle, steel wool pad,
cast-iron frying pan, or other object that contains iron.  It is no longer the same material that
it was before the weathering took place.

   When rust forms, iron combines with oxygen from the air to form iron oxide, a new substance with
different  2………………… Iron, e.g., is attracted by a magnet, but the iron oxide is not.

Sometimes you can observe orange discoloration in a rock and the rock may have become brittle.
Pieces can easily be   3……………. off. The orange color is probably a sign of iron oxide in the rock.
The original rock contained iron or minerals with iron.  A form of chemical weathering known as
oxidation has changed the iron to iron oxide.

   Sometimes when the outer layer is 4…………….. away, the inner rock appears to be a different color.
The outer rock layer has 5……………….. chemical weathering, but the inner has not. Different minerals
have been formed in the outer layer.

   There is some evidence that the freezing of water in rocks creates ideal conditions for chemical
weathering. As water freezes, it 6……………….. 9%. The resulting pressure can force films of water into
micropores and crevasses within the crystal structure of the rock. There the water can  7……………… the
rock chemically.

   A form of chemical weathering known as carbonization causes caves to form in rock material.
Carbon dioxide from the air dissolves in water to form carbonic acid. This weak acid reacts slowly
with some minerals found in rocks. One rock that is  8……………. is limestone. Huge limestone caves can
be formed over long periods of time by running water that contains dissolved carbon dioxide. The
water flows 9……………… underground cracks in the limestone. The carbonic acid continues to dissolve
more and more of the limestone along the surface of the cracks until a cave is formed. As years
pass, the cave becomes larger and may be many meters high and many kilometers long.

   If a small amount of acid is dropped onto a piece of limestone, gas 10……………. can be observed on
the surface. A chemical reaction is  11……………….. The rock  12……………..

carbon dioxide gas as the acid reacts with the limestone or calcium carbonate mineral in the
limestone rock.