I waved to Nancy, but she was ______ in her thoughts, and made no response.
| A．involved | B．stuck | C．absorbed | D．interested |
The factory was built in a secret place, around ______ high mountains.
| A．which was | B．it was | C．which were | D．them were |
Yesterday we visited a modern hospital, around _______ some fruit shops.
| A．which is | B．it is | C．which are | D．them are |
He had thousands of students, many of ______ gained great success in their own field.
| A．whom | B．them | C．which | D．who |
He asked a lot of questions, none of ______ was easy to answer.
| A．which | B．them | C．what | D．that |
He asked a lot of questions, and none of ______ was easy to answer.
| A．them | B．which | C．what | D．that |