题目
---Do you know who ____ the tomb of Emperor Qin and who ___ the mobile phone？
---No，but we may ask our teacher．（ ）
---No，but we may ask our teacher．（ ）
A.
discovered/invented
B.
was discovered/was invented
C.
invented/discovered
D.
was invented/was discovered
知识点：语态的辨析章节：句法 / 被动语态