Прочтите предложения. Сравните и проанализируйте их. Найдите независимый причастный оборот. Помните, что независимый оборот всегда содержит собственное подлежащее.

1. Instructions being obtained, the control unit causes other units to perform the necessary operation.

2. Instructions are obtained, the control unit causes other units to perform the necessary operation.

3. Having obtained the instructions the control unit causes other units to perform the operation.

4. Obtaining the instructions the control unit causes other units to perform the operations.