The morning news says a school bus ______ with a train at the junction, and a group of policemen were sent there immediately.

A．bumped

B．crashed

C．collided

D．struck

某人因交通事故大腿处受伤流血不止，血色暗红，血流速度较慢，正确的止血方法是（    ）

A．从伤口下方止血

B．从消毒纱布包扎

C．从伤口上方止血

D．让血液自然凝固