Mary and I [u]       [/u]  friends. 未知类型：{'label': 'questionDesc', 'content': '请选择正确答案。', 'isMemberControl': 0, 'type': 181} A: am B: is C: are D: be

— What are those? — [u]     [/u] are their books. 未知类型：{'label': 'questionDesc', 'content': '请选择正确答案。', 'isMemberControl': 0, 'type': 181} A: That B: They’re C: They D: This

Tianjin is[u]      [/u]beautiful city in[u]      [/u] north of China. 未知类型：{'label': 'questionDesc', 'content': '请选择正确答案。', 'isMemberControl': 0, 'type': 181} A: a; a B: a; the C: the; / D: /; the

Their [u]      [/u] was calm and expert. A: responsibility B: response C: respond 未知类型：{'label': 'questionDesc', 'content': '请选择正确答案', 'isMemberControl': 0, 'type': 181}

There[u]      [/u]a computer and five books on the desk. 未知类型：{'label': 'questionDesc', 'content': '请选择正确答案', 'isMemberControl': 0, 'type': 181} A: are B: is C: were