The advantage human beings have to the sun is worth discussing.
| A．take of | B．play with | C．have on | D．do with |
___ is better to build house on rock not on sand.
| A．That | B．It | C．This | D．What |
Is the museum ___ we visited last year?
| A．the one | B．where | C．which | D．that |
She needs the work ____ before tomorrow.
| A．done | B．be done | C．doing | D．be doing |
--Did a letter come for me?
--Yes, ___ came for you this morning.
| A．that | B．it | C．one | D．the letter |
He is determined to devote himself to ___ the country.
| A．serve for | B．serve | C．serving for | D．serving |