This is the third time I __________ the Great Wall.
| A．came to visit |
| B．am on |
| C．have come to visit |
| D．am visiting |
It was __________ cold winter night and the moon was shining brightly across __________ night sky.
| A．/; a | B．a; the |
| C．the; a | D．the; / |
Animals are obviously __________ lower form of life than __________ man.
| A．a; / | B．the; the |
| C．a; the | D．/；/ |
There are over 58, 000 rocky objects in __________ space, about 900 of which could fall down onto __________ earth.
| A．the; the | B．/; the |
| C．the; / | D．a; the |
Experts think that __________ recently discovered painting may be __________ Picasso.
| A．the; / | B．a; the |
| C．a; / | D．the; a |
I woke up with __________ bad headache, yet by __________ evening the pain had gone.
| A．the; the | B．the; an |
| C．a; the | D．a; an |