During the first trimester of pregnancy how does it affect the mother

The first trimester is the first 3 months of pregnancy. The 1st month of pregnancy you don't technically know you are pregnant yet until you miss your period. The 2nd month you will be extremely tired, nauseous, and have sore or tender breasts. This is caused from hormones. The 3rd month you will have less morning sickness and maybe have gained a pound or two.

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.