31. We______ on the project for three hours. Let’s have a rest.
| A．are working | B．have been working | C．worked | D．had worked |
Many new houses are said ___ already.
| A．have built | B．to build | C．to be built | D．to have been built |
___ in very good spirits, he worked harder than before.
| A．have built | B．to build | C．to be built | D．to have been built |
The museum ___ at the corner of the street was built in 1879.
| A．stood | B．stand | C．stands | D．standing |
He objected to __ like a child.
| A．be treated | B．being treated | C．treating | D．have been treated |
He found his __ dog yesterday.
| A．losing | B．losed | C．to be lost | D．lost |