The approach to teaching a second language in which children spend the entire day instructed in that second language is referred to as the approach.

Immersion.

Explanation:

Language immersion is essentially a technique created for teaching a second language to individuals, in which the language being taught is used exclusively for instruction. It usually involves learning a new language as naturally as possible, especially to practice the language in its native country but it as it difficult, another option is to immerse oneself in the foreign language in one's own hometown.

answer:

d. because dr. laguardia selected a widely used measure, his study generalizes to has strong external validity. external validity has limited external validity. other applications of this measure.

the widely used measure that he applied to his experiment was the benton facial recognition test. it employed on to football players and as result, only players who suffered brain concussions did not pas this test. and although it has an external validity, it is limited because it isn't general to apply to other population.