▶ Exercise 1 Add semicolons or colons where necessary. Use the delete symbol (7) to eliminate semicolons and colons used incorrectly. If the sentence is correct as written, write C in the blank. Glass is a useful material; it is made from inexpensive raw materials. 1. Glass can take these forms fine like a spider web, heavy like a telescope lens, stronger than steel, or more fragile than paper. 2. The first human-made glass was used as a glaze on ceramic vessels; but it is not known when, where, or how people first learned the glass-making process. 3. Explained very simply, to make glass, use a mixture of sand, soda, and lime cook and cool. 4. The result is: a solid with the properties of a liquid that can be blown, molded, spun, or drawn into endless shapes. Unit 13, Punctuation 265
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