![](https://cos-cdn.shuashuati.com/pipixue-wap/2020-1230-1107-56/ti_inject-812ce.png)
Why do cars need to travel slowly along some suburban roads in the US?
A.
Because children brought up in the suburbs are not accustomed to walking in busy streets.
B.
Because there are no traffic lights in streets in the suburbs.
C.
Because some suburban roads are so bad.
D.
Because some suburban roads are very narrow.