Раскрыть скобки, поставить глагол to beв нужную форму.
The biggest research centre in russia (to be) the russian Academy of Sciences
Every student (to be) interested in this problem last year.
The (to be)at the plant tomorrow.
We (to be) in the laboratory now.
You (to be) in there chemical laboratory a week ago? - No we (not to be). We (to be) there only the day after tomorrow.

The biggest research centre in Russia is the Russian Academy of Sciences.
Explanation: In this sentence, we need to use the verb "to be" in the present tense to talk about the subject "The biggest research centre in Russia." Therefore, we use the form "is."

Every student was interested in this problem last year.
Explanation: In this sentence, we need to use the verb "to be" in the past tense to talk about the action that happened in the past. Therefore, we use the form "was."

She will be at the plant tomorrow.
Explanation: In this sentence, we need to use the verb "to be" in the future tense to talk about the action that will happen in the future. Therefore, we use the form "will be."

We are in the laboratory now.
Explanation: In this sentence, we need to use the verb "to be" in the present tense to talk about the action that is happening at the present moment. Therefore, we use the form "are."

Were you in their chemical laboratory a week ago? - No, we were not. We will be there only day after tomorrow.
Explanation: In the first part of the sentence, we need to use the verb "to be" in the past tense to talk about the action that happened in the past. Therefore, we use the form "were." In the second part of the sentence, we use the negative form "were not" to indicate that we were not in their chemical laboratory. In the third part of the sentence, we use the verb "to be" in the future tense to talk about the action that will happen in the future. Therefore, we use the form "will be."