10、The woman immediately behind the two cars happened to be a learner.
= it happened that the woman behind the two cars was a learner.
happen to：碰巧
 Ex
I happen to hear the news .
It happened that I heard about it the day before yesterday.

11、This made the driver following her brake hard.
Following现在分词做定语修饰driver新概念英语第四册

12、Seeing a cake flying through the air, a lorry-driver who was drawing up alongside the car,pulled up all of a sudden.
draw up = pull up 停车
all of sudden = suddenly

13、The lorry was loaded with empty beer bottles and hundreds of them slid off the back of the vehicle and on to the road.
was loaded with = was filled with
vehicle这里指的是truck lorry

14、It took the police nearly an hour to get the traffic on the move again.
get the traffic on the move 使得车辆开动起来
介词on和名词搭配表示处于某种状态或者某种动作正在进行之中
on the move = move from place to place on 在移动之中
on the rise
on the boil
on the go
on the watch
on the turn
on the run
on the fly
on the increase
on the decrease