I ________ along the street looking for a place to park when the accident ________.
A.went; was occurringB.went; occurredC.was going; occurredD.was going; had occurred在线课程C
解析：
句意：我沿着街道找停车位，这时发生了事故。occur是瞬间动词，此处不用进行体，可排除A项；
且沿街行车与车祸几乎是同时发生，可排除D项；
车祸发生时，车是在行进中，因此C项最佳。此处是when（这时，突然）句式之一。如：①I was watching TV when someone knocked at the door.②I was about to go out when someone knocked at the door.③I had just finished my homework when someone knocked at the door.