In the line "You give your love so sweetly," the phrase "so sweetly" is sung with melismas (F# E | F# E E), giving a sense of degree, and in the line "Is this a lasting treasure," the phrase "lasting treasure" is sung with melismas (B A C# B | C# B B, I think*), lending something of a sense of the durative nature of "lasting."
In the line "When I can feel the magic of your sighs"**, "sighs" is sung with a descending melisma (A G# F#), providing the impression of a sigh.
Of these features, the Shirelles' version (in C major rather than the Zombies' A major) has just a melisma'd "treasure" (E D D) and "sighs" (C A).
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*The second version has a melisma here, too, but it's more complex.
**In the second version, this line is "Well, I recall the magic of your sighs," although in the Shirelles' version, it's "Can I believe the magic of your sighs?"