The phrase "are often complemented by" is correct and usable in written English.
It can be used to indicate that one thing enhances or adds to another, typically in a descriptive or analytical context.
Example: "The flavors in this dish are often complemented by a touch of citrus, which enhances the overall taste."
Alternatives: "are frequently enhanced by" or "are commonly supported by".
The names are often complemented by overwrought accents: think of Daryl Hannah's strangled, guttural Southern drawl in "Steel Magnolias" and Stockard Channing's raw Yankee inflections in "Practical Magic".
In engineering education, concepts taught through lectures are often complemented by laboratory experimentation.
Well-conducted systematic reviews employ comprehensive searches in various databases and are often complemented by hand searches.
These policies are often complemented by specific statutory requirements that direct U.S. EPA to further evaluate and protect children's environmental health.
The visual displays males make to attract a female's attention are often complemented by tactile behavior, such as biting and rubbing of the carapaces.
Together with the rapidly increasing amount of genetic data from free-living populations, these concepts are often complemented by genetic [ 37] or phylogenetic [ 3] species concepts, creating the so-called integrative taxonomic approach.
His drawings were often complemented by amusing quotations.
Today, traditional peer review is often complemented by post-publication peer review through submission of articles to pre-print servers, and bolstered by internal peer review before publication.
Anyone who has seen Katie Mitchell's The Waves will recognise the use of multimedia here in which the staged action is often complemented by large and small screen video close-ups.
The figure is, however, incomplete in that a stream processing system is often complemented by local storage or even part of a regular database system.
Therefore, ChIP-chip experiment is often complemented by functional assays using gene microarray.
