如图所示，在x轴相距为L的两点固定两个等量异种点电荷+Q、-Q，虚线是以+Q所在
题型：选择题
问题：
如图所示，在x轴相距为L的两点固定两个等量异种点电荷+Q、-Q，虚线是以+Q所在点为圆心、L/2为半径的圆，a、b、c、d是圆上的四个点，其中a、c两点在x轴上，b、d两点关于x轴对称。下列判断正确的是（ ）
A．b、d两点处的电势相同
B．四点中c点处的电势最低
C．b、d两点处的电场强度相同
D．将一试探电荷+q沿圆周由a点移至c点，+q的电势能减小
题型：选择题
BUS SERVICE
New York City — Brennan, New Jersey
(Trip time: 30 minutes each way )
Timetable
●Buses leave the Railway Station, New York 7:00 a.m. and every half-hour thereafter(此后) until 11:30 p.m. (7 days a week).
●Buses leave Brennan Station 20 minutes before and after every hour from 6:20 a.m. to 10:40 p.m. (7 days a week ).
●Evening rush hours(5:00 p.m. to 7:00 p.m.) buses leave the Railway Station, New York every 15 minutes (Monday — Friday).
●Holidays: buses leave every hour on the hour time, each direction.
All tickets must be bought at Window 12, the Railway Station, New York, or at the Brennan Station Window before boarding buses.
60. What time does a bus leave New York for Brennan every Thursday?
A. 10:20 a.m. B. 6:30 a.m. C. 6:45 p.m. D. 4:40 p.m.
61. Which is the latest bus you should take from Brennan if you have to arrive at the Railway Station, New York before 4:00 p. m. on Monday?
A. The 3:20 p. m
bus B. the 3:00 p. m bus
C. The 3:30 p. m bus D. The 3:40 p. m bus
62. What time does a bus leave Brennan for New York on Christmas Day
A. 1:00 p. m B. 9:40 a. m C. 3:15 p. m D. 8:30 a. m