Who conducted important research on color vision in the 1920s?

Based on the text, what is the BEST strategy when having a conflict or difference of opinion with a spouse?

a) Press ones' significant other to fully express his feelings. b) Be open and let the feelings all hang out. c) Keep to the issue and don't get personally hurtful. d) Keep angry feelings to oneself.

Having a close other-sex friend

A) is common by mid-adolescence. B) is rare during childhood. C) is considered rewarding, especially by adolescent boys. D) All of the above.