There is no way of knowing why one man makes an important discovery ______ another man, also intelligent, fails.
#30143
A
since
B
if
C
as
D
while
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The news came _______the British Queen’s Mother celebrated her 101st birthday in good health, _____ isn’t surprising，because she lives an easy life and gets the best medical care.
#32387
A
that/which
B
which/which
C
that/that
D
when/as
You should be careful of such a person flatters you in your presence and speaks ill of you in behind.
#33297
A
who
B
that
C
as
D
which
My English has greatly improved , ______ I practice using it every day.
#32021
A
until
B
unless
C
though
D
as