"It would have been bad manners to make his guests feel foolish or uncomfortable." "Bad ma
A.ugly
B.dishonest
C.impolite
D.shameful
A.ugly
B.dishonest
C.impolite
D.shameful
ing hand.
(A) Not being (B) Had it not been (C) Without being (D) Not having been
Before the first non-stop flight made in 1949, it ________ necessary for all planes to land for refueling.
A) would be B) has been
C) had been D) would have been
A.would be shipped already
B.must have been shipped already
C.had been shipped already
D.have been shipped already
If the operation __ carefully prepared, it would not have been successful.
A. was not
B. has not been
C. had not been
D. were not
, it ________ necessary for all planes to land for refueling.
A) would be B) has been C) had been D) would have been
A.would be
B.would have been
C.will be
D.was
The millions of calculations involved, had they been done by hand,__________ all practical value by the time they were finished.
A) had lost B)would have lost C)would lose D)should have lost
A、would have answered
B、should answer
C、answered
D、had answered
In 1870, horses and mules were the prime source of power on U.S. farms. One horse or mule was required to support four human beings—a ratio that remained almost constant for many decades. At that time, had a national commission been asked to forecast the horse and mule population for 1970, its answer probably would have depended on whether its consultants were of an economic turn of mind. Had they been "economists", they would have recognized that the power of steam had already been harnessed to industry and to land and ocean transport. They would have recognized further that would be only a matter of time before steam would be the prime source of power on the farm. It would have been difficult for them to avoid the conclusion that the horse and mule population would decline rapidly.
Which of the following is NOT mentioned by the author as a consequence of new technological developments?
A.Older technologies die away.
B.The quality of life is improved.
C.Overall productivity increases.
D.More raw materials become necessary.
Which of the following sentences indicates a subjunctive mood?
A.Not until nine o"clock yesterday evening did we finish the work.
B.I had been at the bus stop for 20 minutes when the bus finally came.
C.Without your timely arrival, she would have been drowned.
D.If my mother has time, she will take me to the museum.