Ⅰ．用所给单词的正确形式填空

【1】My mother was ______（cook）when I got home yesterday.

【2】—Can you think of any ______（wonder）in the world?

—Yes, such as the Great Wall, the Pyramids and so on.

【3】Do you want to join in the ______（discuss）? It helps you a lot.

【4】Spring is a ______（wonder）season and everything comes to life.

【5】In ______（they）opinion, they should study in groups and help with each other.