Advertising: Refers to the commercial activities of the producer or operator of the product, which directly or indirectly introduces his or her goods or services through a certain medium and form at the expense of the product. Which of the following are not advertised? ['Mengniu Milk Production Sponsors TV Shows.', 'Doctor recommends colleagues to buy Haier washing machine.', 'China Unicom invites Yao Ming as image spokesperson.', 'Close-ups of a certain brand of the mobile phone appear repeatedly in the movie "A World Without Thieves".']