An early typewriter produced letters quickly and neatly; the typist, _____ couldn't see his work on his machine.
| A．however | B．therefore | C．yet | D．although |
A man may usually be known by the books he reads _______ by the friends he keeps.
| A．as well as | B．as if | C．as soon as | D．as usual |
There are so many books! It is not easy for us to decide what to take and what to_______.
| A．take on | B．pick up | C．leave behind | D．work out |
When I try to understand _______ that prevents so many Americans from being as happy as one might expect, it seems to me that there are two causes.
| A．why it does | B．what it does | C．what it is | D．why it is |
The science of medicine, _______ progress has been very rapid lately, is perhaps the most important of all the sciences.
| A．to which | B．in which | C．Which | D．with which |
—Which day do you think is all right to our next meeting?
—You make _______,_______ day is all the same to me.
| A．one;one | B．it;any | C．that; some | D．this; another |