When asked what they would volunteer to do, ________ said they were willing to do something they could.
| A．half of these | B．half of which |
| C．half of whom | D．half of them |
If you’d like to gain more contents from that website, you have to answer some messages ________ personal information.
| A．recognizing | B．requesting |
| C．preferring | D．expressing |
When the mother realized what had happened to her child, she ________ her face in her hands. So no one could see her expression.
| A．ignored | B．damaged |
| C．buried | D．recovered |
I’d love to join in your visit to a local museum today, but I’m on a very tight ________ -I’ve got a lot of work to do today.
| A．identity | B．schedule |
| C．attitude | D．command |
After gunshots fired on campus, there is a growing _________ about safety among teachers and students.
| A．power | B．devotion |
| C．concern | D．identity |
Not until he retired from teaching three years ago ________ having a holiday abroad.
| A．he had considered | B．had he considered |
| C．he considered | D．did he consider |