________, what he has said _______ to be _______ as we haven’t investigated the site yet.

A．Obviously; remains; proved `

B．Fundamentally; is remained; balanced

C．Traditionally; remaining; checked

D．Unbelievably; remains; settled

履带式拖拉机行驶系的作用是承受重量和路面的各种反力及反力矩、吸收震动、（）、保证拖拉机正常行驶。

A、缓和冲击

B、承受质量

C、吸收振动和冲击载荷

D、保证履带正常转动