小题1:The association between IQ and happiness.
小题2:Very happy
小题3:Because the initial costs may be offset by future benefits.
小题4:The interventions are necessary.
小题5:Lower income and poor mental health.
小题1:The association between IQ and happiness.
小题2:Very happy
小题3:Because the initial costs may be offset by future benefits.
小题4:The interventions are necessary.
小题5:Lower income and poor mental health.