The workers ___ busily when the boss came to look for something she ___ in the office.
| A．had worked; had left | B．were working; had left | C．working; had left | D．had worked; left |
（2013·大纲卷）When I arrived, Bryan took me to see the house_ I would Be staying.
| A．what | B．when | C．where | D．Which |
The children,____ had played the whole day long, were worn out.
| A．all of what | B．all of which | C．all of them | D．all of whom |
The museum will open in the spring with an exhibition and a viewing platform____ visitors can watch the big glasshouses being built.
| A．what | B．where | C．when | D．why |
（2013·新课标Ⅱ卷)When I arrived, Bryan took me to see the house_ I would be staying.
| A．what | B．when | C．where | D．Which |
He wrote a letter ________ he explained what had happened in the accident.
| A．what | B．which |
| C．where | D．how |