__________to realize how hard he worked on the book.
A、Only then I came
B、Only then did I come
C、Only then do I come
D、Then did I only come
A、Only then I came
B、Only then did I come
C、Only then do I come
D、Then did I only come
Only when I began to do it ______ that I had made a mistake.
A.I realized
B.I had realized
C.did I realize
D.would I realize
We can realize how deeply a finger is put into water at body temperature ______.
A.from the sense of direct touch
B.through the difference in temperature
C.through skin contact
D.from the even distribution of pressure
Not until ten o' clock______it was too late to return.
A.they realized
B.they did realize
C.did they realize
D.realized they
A. would
B. used to
C. preferred to
D. had to
Williams did not realize his loss for several days because______.
A.he trusted the dog to find the wallet
B.he was unconscious all that time
C.he thought the wallet was in the house
D.he had no occasion to feel in his pockets
A. realized
B.have realized
C.realize
D.should realize
Only then____that she had made a mistake
A.she realized
B.did she realize
C.had she realized
D.she had realized
Not until______ the whole thing to him ______that he was wrong.
A. had I explained, he realized
B. had I explained, that he realized
C. I had explained, that he realized
D. I had explained, did he realize