---How amazing it is that astronauts are exploring outer space！
---It’s a challenge, I guess, man against nature.
| A．of |
| B．for |
| C．by |
| D．about |
It is believed that _____ European scientist invented _______.
| A．an; a television | B．a; a television |
| C．an; the television | D．a; the television |
The shop has been standing so ______ that a thief finds nothing to steal.
| A．quietly | B．lonely | C．empty | D．Open |
The medical reform in that country turned out to be________failure,but as we know,success often comes after ________failure.
| A．a;the | B．a;/ |
| C．a;a | D．/;/ |
I guess we’ve already talked about this before but I’ll ask you again just________.
| A．by nature | B．in return |
| C．in case | D．by chance |
Mothers holding jobs outside the home should have________schedules to make it easier to care for their children.
| A．heavy | B．smooth |
| C．flexible | D．complex |