有人梦见自己到了另一个世界，当他再度睁开眼睛时，发现自己处在一个街角，有一个人慢慢骑着自行车。当他接近时，这位先生惊讶地发现，这个骑车人和自行车在运动方向是不可思议的扁平。这位先生可能涉及的科学理论是（  ）

A．量子力学

B．相对论

C．光电效应

D．进化论

The nurse is reviewing discharge instructions with a client after an uncomplicated delivery. Which of the following symptoms is LEAST important in characterizing postpartum depression

A．Crying easily and feeling despondent.

B．Loss of appetite and anxiety.

C．Altered body image.

D．Difficulty sleeping and poor concentration.