问题
选择题
By the time he ____ at the party, all the other guests ____ playing games.
A．arrived; had begun
B．arrived; began
C．had arrived; began
D．had arrived; have begun
答案
答案：A
考查by的时态。By的用法是，by后面跟什么时态，主句就采用什么完成时，总之by是完成时的标志。 所以选择A