It is not that simple to replace old with young.

A. First, today's situation is transitional, as new technology replaces old.

They often replaced older 2-8-2 Mikados where more power was required.

Moreover, they said, many of the new plants would replace older, dirtier, less efficient ones currently in use.

It replaced old Locks 12 and 13, timber crib structures completed in 1903.

It replaced old Locks 14 and 15, timber crib structures completed about 1903.

It replaced old Locks 10 and 11, timber crib structures installed in 1897-1903.

From 1920 to 1970 death rates in Australian middle aged men stayed roughly constant as new killers replaced old.

In the meantime the highest costs of these changes are borne by those made redundant as new technologies replace old.

To treat himself, he replaced old sliding glass doors with a wall of windows that accentuate the water views.