Passive/active voice

Scientists have identified the following problems.

• Active
• Passive

Adjustments were made to the files.

• Active
• Passive

The conference will be held in July.

• Active
• Passive

A speech will be delivered by the principal.

• Active
• Passive

Staff should use the facilities.

• Active
• Passive

The buildings were checked every hour.

• Active
• Passive