Sentence examples for frequently very difficult to from inspiring English sources
Hierarchy in evolution is commonly presented in phylogenetic diagrams, and the ability to comprehend evolutionary relationships has come to be referred to as "tree thinking," which many authors argue is frequently very difficult to grasp and to teach (Baum and Offner 2008; Gregory 2008; Sandvik 2008; Meisel 2010).
Practicing chemists soon learn, often simply by experience, that it is frequently very difficult to crystallize a newly synthesized substance, while subsequent crystallizations are considerably more facile.
Women may not appear in court, and though they may be divorced via brief verbal declarations from their husbands, they frequently find it very difficult to obtain divorce themselves.
But she added, "Even for those who have met this requirement, we have frequently found it very difficult to verify that fines and fees have been paid".
Duveen Brothers frequently owed Berenson large sums of money, which Berenson found very difficult to extract from the firm.
Cryptic species complexes, in which the component taxa have not diverged morphologically too much, are very difficult to identify and their discovery is frequently a matter of chance.
PCR-ribotypes 020 and 014 are very difficult to differentiate by PCR-ribotyping and, therefore, frequently combined as "014/020 type".
It is very difficult to assess analytical bias as statistical methods are frequently described poorly in many areas of research [70].
Some tumours may have a very dense fibrotic stroma and are very difficult to penetrate, and in these the FNA biopsy is frequently negative.
Gas outburst accidents frequently occur during mining of these seams, therefore the productivity is lower, and it is very difficult to achieve safe and efficient mining.
