In 1948, three American scientists invented ____ transistor, which is ____ small electronic device to control an electric current.
#8790
A
the; a
B
a; a
C
the; the
D
a; the
推荐题目
We live in ____ neighbourhood of the school and go to school on ____ foot.
#8724
A
the; /
B
the; the
C
a; /
D
a; the
It is known to us that without__ passport, travelling abroad is out of ___question.
#9900
A
a; the
B
不填；不填
C
the; a
D
the; 不填
There has been ____rising demand for grain as ____industrial material in spite of the nation’s good harvests.
#10513
A
/;an
B
a;an
C
the;an
D
a;/
Scientists have decided to declare ____ war on AIDS in order to make ____ breakthrough in treating it.
#8228
A
a, a
B
/, a
C
a, the
D
/ , the
They haven’t made ________contact with each other since they had ________quarrel two weeks ago.
#9594
A
the; the
B
不填; a
C
a; the
D
不填; the