1、单选题：
As a high-speed spaceship flies past you, it fires a strobe light that sends out a pulse of light in all directions. An observer aboard the spaceship measures a spherical wave front that spreads away from the spaceship with the same speed in all directions. What is the shape of the wave front that you measure? （ ）
选项：
A:ellipsoidal, with the longest axis of the ellipsoid along the direction of the spaceship’s motion;
B:spherical
C:ellipsoidal, with the shortest axis of the ellipsoid along the direction of the spaceship’s motion
D:not enough information is given to decide.
答案: 【spherical】

2、单选题：
Stanley, who works for the rail system, has carefully synchronized the clocks at all of the rail stations. At the moment that Stanley measures all of the clocks striking noon, Mavis is on a high-speed passenger car traveling from Ogdenville toward North Haverbrook. According to Mavis, when the Ogdenville clock strikes noon, what time is it in North Haverbrook?（ ）
选项：
A:noon
B:before noon
C:after noon
D:not enough information is given to decide
答案: 【after noon】

3、单选题：
Samir (who is standing on the ground) starts his stopwatch at the instant that Maria flies past him in her spaceship at a speed of 0.600c. At the same instant, Maria starts her stopwatch. As measured in Samir’s frame of reference, what is the reading on Maria’s stopwatch at the instant that Samir’s stopwatch reads 10.0 s? （ ）
选项：
A:less than 10.0 s
B:not enough information is given to decide
C:more than 10.0 s
D:10.0 s
答案: 【less than 10.0 s】

4、判断题：
In frame S events P1 and P2 occur at the same x-, y- and z-coordinates, but event P1 occurs before event P2. In frame S’, event P1 occurs first。（ ）
选项：
A:对
B:错
答案: 【对】

5、单选题：
According to relativistic mechanics, when you double the speed of a particle, the magnitude of its momentum increases by （ ）
选项：
A:a factor between 1 and 2 that depends on the mass of the particle
B:a factor smaller than 1
C:a factor of 2
D:a factor greater than 2
答案: 【a factor greater than 2】