求大神解答英语语法填空

求大神解答英语语法填空
In 1998 large numbers of Americans went to Burger King asking for a new type of burger.The food company__(publish) an ad in USA today announcing the new 'left-handed whopper',a burger designed for left-handed people,the following day,burger king __(admit) that they__(joke) all along.
Swedish technician kjell __(work) on the development of colour TV for many years when he __(announce) in1962 that everyone could now convent their black and white TV sets into colour.The procedure was simple:you__(have) to put a nylon stocking over the TV screen.
Pretending that it__(develop) the product for some time,a British supermarket announced in 2002 that it __(invent) a whistling carrot.Using genetic engineering,the carrot grew with holes in it,and,when cooked,it would start whistling.