Autism is a developmental disorder that is characterized by severe behavioral abnormalitiesacross all primary areas of functioning. Its onset is often early; it generally makes itself known
by the age of two and one-half. It is not a single disease entity but is instead a syndrome defined
by patterns and characteristics of behavior; it, therefore, most likely has multiple etiologies rather
than a single causative factor. Autism is not fully understood and thus is controversial with
respect to diagnosis, etiology, and treatment strategies.
1.. The word “primary” in the passage could best be replaced by:
a. elementary
b. main
c. introductory

2.. The word “onset” in the passage is closest in meaning to:
a. placement
b. support
c. beginning