It seems that oil______from this pipe for some time.We’ll have to take the machine apart to put it right.
#104361
A
had leaked
B
is leaking
C
leaked
D
has been leaking
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It is ten months since he ______ a doctor. 
#101164
A
becomes
B
became
C
has become
D
had become
 —What were you doing when I phoned you last night? —I      my painting and was starting to take a bath.
#104680
A
have already finished
B
was finishing
C
had just finished
D
was going to finish
— Why? Tom, your shirt is so dirty! — Mum, I __ my storeroom downstairs。
#104430
A
cleaned
B
have worked
C
was cleaning
D
have been cleaning