The correct answers are: -pexy, -tocia, and -centesis. These are the suffixes that require the combining form of root words to be used. The combining forms are created with the combination of the word root and a vowel. Even though there are some exceptions, <u>the combining vowel is used if the suffix begins with a consonant</u>. If the suffix begins with a vowel (a-e-i-o-u), the combining vowel is not used. For instance, the suffix <em>-centesis</em> (puncture and aspiration of) requires a combining vowel to be used as in “paracentesis”: The doctor performed a paracentesis to remove fluid from the patient’s abdomen.
