a crowd of的用法和样例：
- By the time the ambulance had arrived, a crowd of onlookers had gathered.
- A crowd of cattle were dotted around the grass land with a little boy sitting on a rock.
- Everywhere the foreigner went, he always had a crowd of children trailing behind.
- He did the deed in view of a crowd of people.
- A woman in the middle age comes in, and follows a crowd of child later.
a crowd of的相关资料：