69av久久,人妻丝袜中文字幕久久,久久午夜无码鲁丝片午夜精品

單項(xiàng)選擇題In the horizon system of coordinates what is equivalent to latitude on the Earth?（）.

A.Altitude
B.Zenith
C.Declination
D.Zenith distance

1.單項(xiàng)選擇題In the horizon system of coordinates what is equivalent to the equator on the Earth?（）.

A.Prime vertical circle
B.Principal vertical circle
C.Parallels of altitude
D.Horizon

2.單項(xiàng)選擇題In order for a star to be used for a sight at lower transit，the star must（）.

A.be circumpolar
B.have a declination equal to or greater than your latitude
C.have a GHA of 180°
D.have the SHA equal to or less than the LHA

3.單項(xiàng)選擇題In low latitudes，a first quarter Moon will always rise at about（）.

A.sunrise
B.1200 LMT
C.sunset
D.2400 LMT

4.單項(xiàng)選擇題In general，the most effective period for observing stars and planets occurs during the darker limit of（）.

A.sunset
B.civil twilight
C.nautical twilight
D.astronomical twilight

5.單項(xiàng)選擇題Elongation becomes zero at（）.

A.opposition
B.west quadrature
C.apogee
D.inferior conjunction