尽头线调车时，距车档或尽头站台（）米处必须一度停车。
A、30
B、40
C、50
参考答案：A
She often ______ little brother ______ his homework. [ ]
A. helps; doing
B. helps; do
C. help; to do
D. helps; does
饮酒后驾驶机动车的一次记12分。
