A cactus is covered with a waxy layer to prevent water loss. Which type of tissue is this?

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.

Protesting a law by picketing civil liberty or civil right

National security letters under title v of the patriot act require probable cause contain a gag order provision require judicial review cannot be used against us citizens