—__________ is it?
—It's 2:30.[ ]
A. What
B. What time
C. What day
D. What colour
答案:B
睡眠时相同期,把下列哪一期称“入门期”()
A.NREM第一时相
B.NREM第二时相
C.NREM第三时相
D.NREM第四时相
The wavelengths of light and radio waves, unlike high energy gamma radiation, are much shorter.
A.True
B.False