1. General contractors build residential, industrial and commercial buildings. - Residential, industrial and commercial buildings are built by general contractors 2. They were specializing in one type of construction at that time. – In one type of construction was being specializing at that time.
3. They have just obtained some orders for their work from the general contractor. - Some orders for their work from the general contractor have been just obtained.
4. The electricians installed the building electrical systems last week. - The building electrical systems were installed by the electricians last week.
5. The insulation workers had covered structures with insulating materials by the end of the week. - Structures with insulating materials had been covered by the insulation workers by the end of the week.
6. The plumbers are maintaining many different types of pipe systems now. - Many different types of pipe systems are being maintained by the plumbers now.
7. The plasterers will apply concrete to exterior walls in a week. - Concrete to exterior walls will be applied by the plasterers in a week.
8. They will have planned the job by the end of the month. – The job will have been planned by the end of the month.