- 搜標(biāo)題
- 搜題干
- 搜選項(xiàng)
單項(xiàng)選擇題
A tide is called diurnal when（）.
A.only one high and one low water occur during a lunar day
B.the high tide is higher and the low tide is lower than usual
C.the high tide and low tide are exactly six hours apart
D.two high tides occur during a lunar day
