百花大教堂位于意大利（）。
参考答案：佛罗伦萨
While Helen ______ the piano, her mother came in.[ ]
A. was playing
B. is playing
C. played
D. plays
英译汉：“health certificate”，正确的翻译为( )。
A．健康证书 B．品质证书C．植物检疫证书 D．熏蒸/消毒证书
