To "impose on" someone means to take advantage of them by making an unreasonable request or by intruding.

All the swimmers have improved ____ their previous best performance.
(a) from (b) on (c) in (d) to

To "implant in" someone means to establish an idea or attitude in their mind.

As there was no train until the late evening he had to imposed himself ____ his hosts for longer than he had intended.
(a) on (b) in (c) with (d) from

The verb "impelled" means to drive, force, or urge someone to do something. The correct preposition is "to."

The revolutionary leaders implanted ____ the peasants the determination to take and own the land on which they worked.
(a) on (b) down (c) in (d) at

The verb "immersed" is followed by the preposition "in," which means to be submerged in a liquid.

The cabinet was impelled ____ extreme measures.
(a) to (b) with (c) in (d) into

The verb "hurl" is followed by "at" when something is thrown towards a target.

When a body is immersed ____ a fluid it apparently loses weight.
(a) with (b) to (c) on (d) in

The phrasal verb "hope for" means to want something to happen.

The streets were littered with stones and bottles hurled ____ the policemen.
(a) on (b) at (c) upon (d) to

The phrasal verb "hedged round" means to be confined or limited by something. "Hedged about" and "hedged around" are also common, but the answer key specifies "round."

The best one could hope ____ was to attract no attention either way.
(a) for (b) with (c) in (d) to

The phrasal verb "hedged about" means to be surrounded or restricted by something.

Their life was hedged ____ with petty restrictions.
(a) around (b) about (c) round (d) at

The verb "harmonize" is followed by the preposition "with" when it means to be in agreement or accord with something.

Starting a new business is hedged ____ financial and staffing problems.
(a) in (b) about (c) out (d) over

The phrasal verb "hang on" means to hold on tightly or to wait for a short time.

His temperament does not harmonize ____ a slow, even pace of life.
(a) with (b) in (c) to (d) into