-----I called you yesterday evening, but you were not in.-----Sorry, I _____ in the shop with my mother.
–Tom, you didn’t come to my party last night? – I ________, but my mom hurt her back and I had to look after her.
Their school looks quite different from _______ ten years ago.
We must try our best to stop pollution ______ a low-carbon(低碳)life.
–I think honesty is the most important thing in doing everything. –__________ .
Four hundred dollars for just a pair of shoes? You ______ be joking!