The possibility of a way out of the difficulty never _____ to the captain and his crew.
| A．happened | B．occurred | C．appeared | D．flashed |
The number of students from the north ____small.
| A．are | B．is | C．have | D．has |
A number of students _____from the south.
| A．are | B．is | C．have | D．has |
No one except my parents _____anything about it.
| A．know | B．knows | C．is knowing | D．have known |
This pair of shoes ____made in Nanjing.
| A．is | B．are | C．have been | D．had been |
Between the two rows of trees _____the teaching building.
| A．stand | B．stands | C．standing | D．are |