The phrase "appear to drop" is correct and usable in written English.
It can be used when describing a situation where something seems to decrease or diminish in quantity, quality, or intensity.
Example: "The temperature appears to drop significantly during the night."
Alternatives: "seem to decrease" or "look like they are falling".
That leak alone, if confirmed, would appear to drop a heavy hint as to the direction of the new trilogy.
In another room, broken black floorboards appear to drop off into a blank void pierced only by a wide-open eye.
The two-course menu changes each night but the standard doesn't appear to drop – fine Tasmanian hams and beef are on offer, as well as impressively flavourful vegetarian options.
Although reduced cerebral blood flow and oxygenation occur in sepsis, they do not appear to drop low enough to threaten neuronal viability or cause electroencephalogram changes at least in preclinical models of SAE [31].
If it were accelerating, and if a light beam were to enter one side, then, due to the elevator's motion, the beam would appear to drop or curve down as it crossed the elevator.
Humans from another world would appear to drop down from the sky and meet in the embassy they have asked Raël to build for them and share their advanced scientific knowledge with humanity.
Diego Costa's head still appears to drop the moment something does not go his way.
BLYTHEWOOD, S.C. – Rick Perry appeared to drop his attacks against Mitt Romney for practicing what Mr. Perry has called "vulture capitalism".
The next month, the government appeared to drop its threats and be willing to co-operate over BP's demands.
Nibali had appeared to drop out of contention as he struggled up the climbs in the Dolomites last weekend.
Appearing with Mr Brown, Jim Murphy, Labour's leader in Scotland, appeared to drop his guard and depart from the party's "no deals" line.
