By the age of 2, most toddlers will have a vocabulary of about ____

A rigorous study conducted by the Swedish army showed that young men who were heavy cannabis users by age 18 were __________ times more likely to develop schizophrenia than those who weren't.

A. 3 B. 4.5 C. 6 D. 10.3

Manipulating the environmental variable that you think has an influence on some

behavior and then measuring that behavior is called the ____ method. (a) survey (b) experimental (c) control group (d) correlational (e) none of the above