How long does it take diatomaceous earth to kill bed bugs?

Why are people more likely to marry individuals with social and cultural backgrounds very similar to their own? a. parents and other family members always exert pressure to marry within the group. b. people spend a great deal of time alone, and therefore can have few opportunities for meeting people. c. people develop irrational fears of out-group members and are scared to date them. d. people have greater access to individuals like themselves.

Bonus question: according to wikipedia, in chinese philosophy yin and yang "describes how seemingly opposite or contrary forces may actually be complementary, interconnected, and interdependent." what are some examples from the story that amy tan may have intentionally incorporated elements of yin and yang philosophy into this story? select 2.

Why is it economically necessary for the east germans to build berlin wall