_____ do you write to your parents?—Once a month.[ ]

They poured waste water the river. [ ]

Do you know Xidan Girl?—Of course. She played _____ guitar and sang song in the 2010 Spring Festival Gala.

Would you like to watch the 2014 Nanjing Youth Olympic Games this summer holiday?—I’d love to. I believe it ________ be fun.

His mother was born in Greece, and Greek was her native language, ___.