Прочтите текст, выпишите предложения, в которых сказуемое выражено формами страдательного залога. Although joint ventures

1. Although joint ventures have been used for decades as a way to organize a business, in recent years they have been used much more widely. - Present Perfect Passive Voice. 2. They have enjoyed such a surge of popularity, in fact, that more joint ventures have been announced since 1981 than in all previous years. - Present Perfect Passive Voice. 3. Many joint ventures are not intended to fill standard business objectives (such as making profits).- Present Simple Passive Voice. 4. Instead, they were created to learn a technology, open a market and block a competitor. - Past Simple Passive Voice.