A) My friend is happy today. – My friend was sad yesterday.
B) My parents are at work today. – My parents were at home yesterday.
C) Children aren't noisy today. – Children were quiet yesterday.
D) Is our teacher at school today? – Our teacher was at the museum yesterday.
E) It isn't cold today. – It wasn't warm yesterday.
Ты отлично справился с заданием! Продолжай в том же духе, и у тебя все получится!