He and his mother ______ at home last night. [ ]
A. are
B. is
C. was
D. were
答案:D
男士应注意绅士风度,上楼上车应男先女后,下楼下车应女先男后,必要时男士要帮助女士。()
SDH中STM-1的速率是多少?STM-64的速率是多少?