单项选择题
A.the Sun，Earth，and Moon are at right angles B.the Sun's declination is 0°and is moving south C.an inferior planet is at the maximum angle to the line of sight to the Sun D.the Earth is between a planet and the Sun
A.water depth exceeding 100 feet B.fetch C.wind's velocity D.duration of the wind
A.at elongation angles near 180° B.from quadrature to opposition C.at conjunction D.at opposition