Study the words in the box. Circle only the words that can be used as either a noun
or a verb. Check a dictionary if you're not sure. (Hint: You should circle 12 words.)

1 problem
2 percent
3 study
4 subject
5 conduct
6 document
7 solve
8 proof
9 time
10 test
11 experiment
12 state
13 learn
14 basis
15 reading
16 determine
17 observe
18 step
19 lead
20 results
​