I. 1/ a, 2/a, 3/c,4/a, 5/a, 7/c, 8/a, 9/b, 10/c;
II. 1/ - , - ; 2/a, -, a, -, a; 3/ - ; 4/ a, - ; 5/a,-; 6/-, a, - ; 7/ an; 8/a, the; 9/-, the, the; 10/a,the,-, - .
III. 1/ came, had cooked; 2/ returned, had done; 3/ entered, had opened; 4/had given, bought; 5/showed, had drown; 6/ gave; had brought; 7/saw, had not washed; 8/understood, had not done; 9/knew, had not come yet;10/had returned; 11/returned; 12/had finished; 13/finished; 14/thought, had lost; 15/told, had seen; 16/woke up, had gone; 17/thought, had not come; 18/told , had cooked; 19/had found, lost; 20/came, had left.