【单选题】Questions 11 and 15 are based on the following passage. That people often experience trouble sleeping in a different bed in unfamiliar surroundings is a phenomenon known as the “first-night” effect....
A.
She analyzed the negative effect of irregular tones on brains.
B.
She recorded participants’ adaptation to changed environment.
C.
She exposed her participants to two different stimuli.
D.
She compared the responses of different participants.
【简答题】Light of wavelength 600 nm illuminates a diffraction grating. The second-order maximum is at angle . How many lines per millimeter does this grating have?