.
When ___ help, one says “Thank you” while when _________ help, one asks “Can I help you?”
| A．offered; offered | B．offering; offered |
| C．offering; offering | D．offered; offering |
Edison asked his father why the hens could hatch eggs ___he couldn’t.
| A．as | B．and | C．when | D．while |
The new suspension bridge ___by the end of last month.
| A．has been designed | B．had been designed | C．was designed | D．would be designed |
--How often do you attend the evening classes?
---_____, three times per week.
| A．On the whole | B．On average | C．Little by little | D．In all |
The sun was shining brightly, ____ everything there look more beau
tiful.
| A．making | B．to make | C．made | D．having made |
---May I use your computer, Alex?
---Sorry. Mine _____.
| A．has repaired | B．is being repaired | C．has been repaired | D．is repairing |