The great scientist became world-known in the early 1970s,______ he and another scientist made new discoveries about black holes.
#73597
A
which
B
where
C
when
D
then
推荐题目
. It is only when you nearly lose someone ____________ you fully realize how much you value him.
#70604
A
do
B
then
C
will
D
that
Tomorrow is Sunday. Jim will go hiking with his friends if it ________.
#41360
A
isn’t rain
B
doesn’t rain
C
won’t rain
D
don’t rain
Though the key was pressed, nothing ______ on the screen.
#41230
A
appeared
B
was appeared
C
appears
D
is appeared
Have you ever seen any trees ________ leaves were black because of the polluted air?
#66808
A
whose
B
that
C
which
D
who
While having our dinner, _______.
#68160
A
the door bell rang
B
our newspapers came to the door
C
we heard the door bell ringing
D
the postman brought several letters to us