问题
选择题
| The abacus _____ invented in the sixth century by Chinese people. |
A. be B. is C. was D. were |
答案
答案：C
搜题请搜索小程序“爱下问搜题”
| The abacus _____ invented in the sixth century by Chinese people. |
A. be B. is C. was D. were |
答案：C