Circle the correct option to complete the sentences.
As I (waited/ was waiting) for bus, I (saw/ was seeing) Joe crossing the road.
As I (waited/ was waiting) for bus, I (saw/ was seeing) Joe crossing the road.
Hành động "chờ xe buýt" kéo dài → dùng quá khứ tiếp diễn: was waiting.
Hành động "thấy Joe" xảy ra ngắn, bất ngờ → dùng quá khứ đơn: saw.
Dịch: Khi tôi đang chờ xe buýt, tôi thấy Joe băng qua đường.