Перепишите след. предложения; подчеркните в каждом из них глагол-сказуемое и определите его видо-временную форму и залог. a) 1. today scientists are still looking for the substance as a source of energy. 2. the mendeleyev system has served for almost 100 years as a key to discovering new elements. б) synthetic rubber products were developed between 1914 and the 1930s. 2. the intensity of this process is influenced by many factors.
2has served-Present Perfect Active
б)
1were developed-Past Simple Passive.
2is influenced-Present Simple Passive