The problem with self-selection in research is that a. it violates ethical guidelines. b. it makes causal interpretations difficult. c. people often overestimate their own contributions to the research. d. people are often unaware which condition they should choose to be in.

i bought a new phone

explanation:

i will send you the money when i get back from lunch

world war i had a devastating effect on german-americans and their cultural heritage. up until that point   german-americans, as a group, had been spared much of the discrimination, abuse, rejection, collective mistrust experienced by so many different racial and ethnic groups in the history of the united states. indeed, over the years, they had been viewed as a well integrated and esteemed part of american society. all of this change with the outbreak of war.  

b because thats the naswer i got

answer; automatic fire suppression system;