Professor Jordon is well known for his _____ into the habits of the common housefly.
| A．examination | B．introduction | C．research | D．expression |
The two brothers carried a ______ bed into the room.
| A．double | B．deal | C．slight | D．opposite |
It is difficult for you to ______ what will happen in space without gravity.
| A．depend on | B．have some idea of | C．keep from | D．equip with |
The ______ in the mountain village struck most of the visitors.
| A．scenes | B．space | C．absence | D．flight |
Since we have met again after all these years, let's ________ each other from now on.
| A．keep up with | B．keep out of | C．keep in touch with | D．keep touching |
Have you found his name ______ in the papers?
| A．signing | B．signed | C．to sign | D．sign |