Question

passive voice....

1-lincoln emancipated four million african slaves.
2-we propose to build a dam for irrigation purposes.
3-alas! we shall hear her voice no more.
4- india won the cricket match

Answer 1

1)Four million African slaves were emancipated by Lincoln.
2)A dam for irrigation purposes​ was built by us.

Answer 2

Four million African slaves were emancipated by Lincoln.

A dam for irrigation purposes is proposed to be built.
It is proposed by us to build a dam for irrigation purposes.
To build a dam for irrigation purposes is proposed (by us).

Alas! Her voice shall be heard no more.

The cricket match was won by India.