Sentence examples for more challenging are from inspiring English sources
"More challenging are the other overlaps," Kees continues.
More challenging are options to enhance upconversion efficiencies by manipulating emission and excitation processes through plasmonic coupling [61].
Even more challenging are portable reforming applications where the membrane must integrate into fuel processing systems typically operating at much lower pressures than stationary industrial systems, in order to meet strict size, weight and rapid start-up requirements.
Or, still more challenging are scenarios whereby two disparate sources such as a marine basalt and a wind-blown dust of broad continental crust composition are both authigenically altered to, for example, assorted smectites, and thus have the potential to appear as a single source.
More challenging are explanations for the discordant positions of Presbytis and the African genera among colobines in phylogenies revealed by mobile elements and nuclear sequence data.
More challenging are genes that have no recognizable homolog in other existing lineages as is the case for the thousands of intriguing orphan genes (or ORFans [ 52]) and gene families in extant genomes, whose evolutionary histories remain unaccounted for because they are present in only a small group of closely related organisms [ 53].
More challenging is the personal statement itself.
More challenging was Feig's way of working.
More challenging is their long term goal of achieving zero consumer waste as well.
More challenging is the problem of implementing what is called generalization.
More challenging is the devastatingly sour eba, a kind of fufu made from fermented ground cassava.
