8. In a 2017 study designed to investigate the effects of exercise on second-language learning, 40 subjects were randomly assigned to one of two conditions: an experimental group that engaged in simultaneous physical activity while learning the vocabulary in a second language and a control group that learned the vocabulary in a static learning environment. Researchers found that learning second-language vocabulary while engaged in physical activity led to higher performance than learning in a static environment. Complete parts (a) and (b) below. a. What features of a well-designed controlled experiment does this study have