A Dead language is a language which is no longer in everyday spoken use. Obsolete means no longer used, which is similar, but 'Dead language' is the specific term. A Linguist is one skilled in languages. Ancient means belonging to the very distant past.

A Dead letter is a letter that is undeliverable and unclaimed. Illegal means contrary to law. Anonymous means not identified by name. Posthumous means occurring after death.

Anonymous means (of a work or letter) not identified by name. Ambiguous means open to more than one interpretation. Posthumous means occurring after the death of the originator. Manuscript means a document written by hand.

Ambiguous means open to more than one interpretation or having a double meaning. Anonymous means not identified by name. Extempore means spoken or done without preparation. Obsolete means no longer produced or used.

The verb "wrestled" is followed by the preposition "with," which means to struggle or grapple with a problem.s

The phrasal verb "walked into" means to fall into a trap or difficult situation.

There doubts, long wrestled ____, were now resolved.
(a) with (b) to (c) in (d) on

The verb "vouch" is followed by the preposition "for," which means to guarantee or affirm something.

He loves to set traps for the unwary: You would not be the first to walked ____ one.
(a) in (b) into (c) upon (d) onto

The phrasal verb "turned over to" means to hand over control or responsibility to someone.

If you needed a reference, I am sure he would vouch ____ me.
(a) for (b) to (c) in (d) into

The verb "trespassed" is followed by the preposition "upon," which means to intrude on something.

The day-to-day management of the firm has been turned ____ to somebody appointed from outside the company.
(a) in (b) over with (c) over to (d) over on

The verb "testified" is followed by the preposition "for," which means to give evidence or support for something.

No one's privacy is so sacred that it can not be trespassed ____ occasionally.
(a) upon (b) on (c) in (d) into