5. --- My grandmother ______ dancing as a hobby in her sixties, and she is really good at it now.
--- It’s never too old to learn.
| A．dressed up | B．took up |
| C．looked up | D．put up |
What the boy said sounds ______.
| A．reason | B．reasonable | C．reasonably | D．Reasoning |
I didn’t know ______.
| A．where does he live | B．where do he lives |
| C．where he lives | D．where he lived |
Mary sings English songs well and ______.
| A．Jane does too | B．either does Joes | C．so Janes does | D．so does Jane |
I mean ______ class meeting on Monday afternoon.
| A．have | B．to have | C．having | D．to having |
Beijing is one of the ______ in the world today.
| A．busiest city | B．busiest cities | C．busy city | D．busy cities |