问题
选择题
By the time he got there, the party . [ ]
A. begin
B. began
C. had begun
D. has begun
答案
答案：C
搜题请搜索小程序“爱下问搜题”
By the time he got there, the party . [ ]
A. begin
B. began
C. had begun
D. has begun
答案：C
、Cl-
、
、Ca2+、K+