下列字母的大写字母都是两笔的是________。

Nelson Mandela was       of South Africa from 1994 to 1999.

— Have you 　　　 watched any of James Cameron’s movies before? — Yes. I like his movies. Both Avatar and Titanic are my favourites.

-Is your brother running in the park? -No,           is swimming in the river.

--      are the blue hats on sale?   -- They are on sale for 100 dollars．