Only after he realized the significance of mastering two languages __________ English carefully.
| A．did he set about learning | B．did he set out learning |
| C．had he set about learning | D．had he set out learning |
The managing director promised that he would _____ me as soon as he had any further information.
| A．communicate | B．notice | C．notify | D．note |
These plastic flowers look so _____ that many people think they are real.
| A．beautiful | B．natural | C．artificial | D．similar |
When the big bills for mother's hospital care came, father was glad he had money in the bank to _____.
| A．fall short of | B．fall through |
| C．fall back on | D．fall in with |
The farmers were more anxious for rain than the people in the city because they had more _____.
| A．at length | B．at last | C．at stake | D．at ease |
It is clear that the whole world is passing through a social revolution in which a central _____ must be taken by scientists and technologists.
| A．process | B．attention | C．measure | D．part |