Поставить предложения в пасиве .. scientists observed the tigers for six days. scientists are investigating the possibility of life on other planets. when we walked into the classroom, the teacher had already given the assignment. some teachers cleaned up the teachers' room. i think the students will have drunk most of the coffee by the time we arrive. people believe that san francisco is a warm city. made the coffee. 's cat broke the vase. everyone thinks that san francisco is the most beautiful city in the us. our findings will intrigue the world. someone will tell us by this time next week. many people visit disneyland every year. someone has washed the dishes. someone poisoned 's dinner. what happened to you last night? john needs to have someone fix his car. wants to have someone clean her house.

The tigers were observed for six days.
The possibility of life on other planets is being investigated.
When we walked into the classroom, the assignment had already given by the teacher.
The teachers' room are cleaned up by some teachers.
I think most of the coffee will have been drunk by the students by the time we arrive.
San Francisco is believed to be a warm city.
The coffee was made.
The vase was broken by the cat.
San Francisco is thought by everyone to be the most beautiful city in the US.
The world will be intrigued by our findings.
We shall be told by this time next week.
Disneyland is visited by many people every year.
The dishes have been washed.
Dinner was poisoned.
What happened to you last night? Непереходные глаголы не имеют формы страдательного залога.
Someone is needed to fix John's car.
Someone is wanted to clean her house.