— No one can answer the question _______ we can complete the task in time, do you know? — Yes, and this is because we don’t know the way _______ the scientist used last time.
________, no one is sure who discovered America .
As I ______, I suddenly remembered that it was your birthday.
The history of nursing ___ the history of man.
– Do you enjoy listening to records? --- I think records are often ______ an actual performance.
– Does this bus go to the 84th street? --- No, 30th street is _______.