It was______ she went back home______ Kate realised she had left her schoolbag at school.

A．when; then

B．not; until

C．only; when

D．not until; that

车辙试验主要是用来评价沥青混合料的( )。

A．高温稳定性
B．低温抗裂性
C．耐久性
D．抗滑性