He looked at the envelope and __________ Jenny’s handwriting immediately.
| A．understood | B．knew |
| C．recognized | D．recovered |
With the rapid growth of population, the city______ in all directions in the past five years.
| A．spreads | B．has spread | C．spread | D．had spread |
The bell______ the end o f the period rang and we had to stop our discussion.
| A．indicating | B．indicated | C．to be indicated | D．being indicated |
The question is ______can be put into practice.
| A．how you have learned | B．how what you have learned |
| C．that why you have learned | D．how that you have learned |
The announcement ______all flight were cancelled because of bad weather greatly distressed the waiting passengers.
| A．that | B．which | C．why | D．of which |
I haven’t decided _____ hotel to stay at.
| A．which | B．what | C．at which | D．where |