Thomas Alva Edison didn’t “invent” the light bulb (灯泡), but rather he ______ a 50 –year –old idea, which is not well –known.
---- Have you been here long? ---- _______.
________ mud on his trousers brushes off easily.
The young lady was careful _________.
________ their inexperience, they’ve done a good job.
Though they had a meeting yesterday, there is still much that remains______.