判断题
Animal communication systems can be used to refer things which are present or not.（）
正确(↓↓↓ 点击‘点击查看答案’看答案解析 ↓↓↓)
单项选择题 The health club（）I am a member meets once a week.
单项选择题 “It’s at this college（）your father studied（）he was young”，said the mother.
单项选择题 An （）is a scientific test that is done to study what happens and to get new knowledge.
