unusual occurrence; variation; mutation
alternating between happiness and anxiety; swinging between joy and sorrow; being glad and sad by turns; oscillating between optimism and pessimism
passing each other; missing (meeting) each other; failing to meet; (being at) cross purposes; discrepancy
somehow; for some reason or other
refined; elegant; graceful; modest; reserved; restrained
looking pale; looking unwell
middle; halfway; half (of); one half; half (e.g. done, jokingly); partly
diagnosis; medical examination
palpitation (of the heart); pounding; throbbing; thumping
heart sound; cardiac sound
preliminary step; first step
(practical) experience; personal experience; hands-on experience; first-hand experience
immature form (of an organism); young animal
as one had hoped; as one wishes
variables; uncertain elements; uncertainties; imponderables
complementation; supplementation; completion
to shift something to; to move something into; to transfer; to transpose; to exchange; to displace
conformity; compatibility; adaptability; congruity; congruence
shortish; rather short; somewhat short
century; hundred years; (fig.) a long time
minute adjustment; fine-tuning
babies and preschool children
young child; toddler; child over 1 but not yet of school age
substitution; replacement; permutation; substitution; displacement
the prospects look brighter; there is hope of accomplishing (something)
to give up (all thoughts of); to abandon; to despair of; to make up one's mind; to make a decision; to decide
lowish; somewhat low; on the low side; low (ball)
renewal; update; replacement; renovation; breaking (a record)
original; unique (e.g. product); signature; exclusive
divergence; ramification; bifurcation; branching off
unmistakable; evident; obvious; certain; beyond doubt
to tell X from Y; to distinguish; to know (one thing) from (another)
congratulations!; well done!; best wishes!; all the best!
derivation; development; offshoot
possessiveness; desire to monopolize (monopolise); desire for control