单项选择题

Which of the following does an astronomical time clock do？（）

A.Determines the ambient light at night with a photocell.
B.Calculates sunset and sunrise times based on geographical area.
C.Determines the start and end of each of the seasons.
D.Synchronizes the local time displayed with the official world time.

点击查看答案

上一题目录下一题

相关考题

单项选择题

Wires that are installed in air returns above a ceiling must be（）

A.fire proof
B.fiberglass coated
C.plenum rated
D.teflon coated

单项选择题

Which of the following is the recommended placement of the rear surround speakers in a 5.1 surround installation？（）

A.Directly to the left and right and slightly in front of the listener
B.Directly to the left and right and slightly behind the listener
C.Above and behind the listener
D.Directly behind the listener

单项选择题

If the speakers in an installation are out of phase， this means that（）

A.the subwoofer is at the wrong angle.
B.the front and rear speakers are reversed.
C.the polarity of the speakers are reversed.
D.the angle of the speakers are incorrect.