In comparison to the amount of time mothers in typical U.S. two-parent households today spend with their children during the weekend, the typical father spends about ___ as much time

The fact that humans are more motivated to protect the children of their siblings and kin than the children of strangers is explained by _________

Fill in the blank(s) with the appropriate word(s).

The words polydrug and polysubstance describe the use of synthetic drugs (as in polymer) rather than naturally occurring substances (like marijuana).

a. true b. false