English Skills 10th Edition by John Langan, Zoe Albright

Exercise 24

In each outline, cross out the items that do not support the opening point. These items must be omitted in order to achieve paragraph unity.
The twentieth century achieved much toward the control of infectious diseases.
a. Penicillin and other antibacterial medicines were discovered.
b. Sanitary sewer systems were built in many cities.
c. School lunch programs offered low-cost meals to students.
d. Many communities developed water purification systems.
e. More was learned about psychological diseases.