Нужно вставить слово "when"(когда).
#1
1 such a
2 so
3 such an
4 so
5 so
6 such a
#2
1 such a
2 such
3 such
4 such a
5 such a
6 such
Ответ:
1 Their mother saw them play ( playing) chess.
2 Their parents watched them decorate ( decorating) the Christmas tree.
3 I saw him take( taking) his dog for a walk.
4 We heard them play ( playing) the piano in the next room.
5 The teacher listened to him retelling the text.
6 I felt somebody step on my foot.
7 I didn't notice her take my book from the table.