The phrase "occur constantly" is grammatically correct and can be used in written English.
It means to happen or take place frequently and consistently. Example: In tropical regions, rain showers occur constantly throughout the day.
Chemical reactions occur constantly within the food and between the food and its surroundings.
The Nauru files reveal that threats of, attempts at and instances of self-harm occur constantly, sometimes daily.
Farm-based outbreaks of bird flu still occur constantly in a number of countries, although not in Europe.
Natural experiments involving twins and twin-like individuals occur constantly, driven largely by artificial reproductive technology and increased adoption rates.
The odour of excreta (mucus, urine and casts) of Aporrectodea giardi also attracted H. nitidus but this attraction was weaker and did not occur constantly, possibly due to interactions with light and aggregation pheromones.
Organisms must evolve or adapt to changing environments, and it is clear that mutations, which are changes in the sequence of nucleotides in an organism's DNA, occur constantly in all organisms.
With changes occurring constantly, automated quality assurance is paramount.
A groundwater exfiltration flux occurred constantly from a seepage area regardless of rainfall conditions.
Saturated lateral flow over the bedrock surface occurred constantly in the region downslope of the seepage area.
The interferences of dissolved oxygen towards the electrochemical immunosensors occurred constantly, which will restrict the practical clinical application of electrochemical immunoassay.
In consideration that bacterial resistance to such antibiotics has occurred constantly, several newly designed pseudosubstrate oligonucleotides as DNA topoisomerase IV inhibitors have been examined during our recent investigations.
