中国大学MOOC: Please ___ to the rail while walking along the bridge.
举一反三
- One day while I ______ along the street, I ______ someone calling. A: walked ;was hearing B: was walking; has heard C: was walking; heard
- While walking along the icy river banks, we could see cracks in the ice _____ in all directions.
- The Seven Mile Bridge a segmental bridge.
- 中国大学MOOC: Please ___________ ( = dont move) while I connect your I.V.
- The western section of the Bay Bridge is a single suspension bridge.