"they entail" is correct and usable in written English.
You can use it to indicate that one thing requires or involves another. For example, "Working as an engineer entails a lot of responsibility."
Like all intelligent photographs they entail ambiguity.
Guarantees are popular because they entail no immediate cost.
They are formidable, to be sure, but they entail hikes, not climbs.
Sports, physical contests pursued for the goals and challenges they entail.
The Democrats will champion civil unions and all the legal rights they entail.
Sports are defined as physical contests pursued for the goals and challenges they entail.
His powers remain unclear, and Mr. Bush is right to insist that they entail "real authority".
(He does not like owning a lot of physical assets and the risks they entail).
They entail serious social commentary but are sprinkled liberally with wit.
And there is no way to avoid its threats or escape the battles they entail.
These reforms have been opposed by teachers' unions, in part because they entail overall cuts in education spending.
