Нужно переделать предложения в passive voice по примеру.

V. Make the sentences Passive.

Model: They fit this stop valve in the main steam supply line.

This stop valve is fitted the main steam supply line.

1. We usually refer to certain fittings as boiler mountings.

2. They mount safety gives in pairs to protect the boiler against overpressure.

3. We may make a provision for injecting water treatment chemicals.

4. At opposite ends of the boiler they fit water level gauges or "gauge glasses”.

5. We use low level alarm to provide audible warning of low water level conditions.

6. Cocks and pipes connect the glass tube to the boiler shell.

7. Front and back metal plates with the glass plates and a centre metal plate between make up the assembly fun as a "sandwich".

8. We must take care to ensure all round tightening of the bolts.