单项选择题
Other than the Sun and Moon，the brightest object in the sky is（）.
A.Sirius B.Canopus C.Venus D.Jupiter
单项选择题 Opposition occurs when（）.
单项选择题 On mid-ocean waters，the height of a wind-generated wave is not affected by the（）.
单项选择题 Mars will not be visible（）.
