The standard way to hard-boil eggs-ten minutes in boiling water is far from ideal, according to physical chemist Herve This. Egg whites and yolks are made up of protein and water. yolks contain fat as well. As eggs cook, their ball protein uncoils into strands, and the strands bind together to form an intricate mesh that traps water, in essence, the proteins form a gel, a liquid dispersed in a solid. Boiling causes too many egg proteins to bind and farm dense meshes, yielding rubbery egg whites and sandy, grayish yolks. 

But exploiting egg-protein chemistry allows egg cooking to be very precisely calibrated. Ovo transferrin, the first of the egg-white proteins to uncoil, begins to set at around 61℃. Ovalbumin, the most abundant egg-white protein, coagulates at 84℃. Yolk proteins mostly fall in between, with most starting to solidify when they approach 70℃. Using a laboratory oven, Dr. This cooks eggs at 65℃ for about an hour, timing not being critical. The results, with the whites delicately set and the yolks still orange and soft, make it clear why 65-degree eggs are becoming the rage among chefs in France. (Salmonella cannot survive more than a few minutes at 60'C, so a 65-degree egg cooked for an hour should be quite safe.)

Some zoo animals-cheetahs, pandas, and black rhinos, for instance-are reluctant to breed in captivity, while others are too                 , creating a problem for zoos when there is no more room in the cage.

The (i)                 that one occasionally finds in the columnist's articles are so memorable that many people think of her as being far more (ii)                 than she in fact is.

Pine stumps have been found in discrete layers in peat deposits throughout western Europe and thus represent brief but distinct episodes of bog colonization by pine. Their occurrence implies conditions on the boa surface suitable for colonization, followed by inhospitable conditions for trees that nevertheless facilitated preservation of stumps. Thus, the (i)      of pine stumps can (ii)      climate change, by (iii)      the inference that bog surfaces had dried sufficiently to allow colonization and then became too wet to support the trees.

Although the venerable paradigm of the balance of nature is (i)      scientists studying evolution and ecology, the idea is aesthetically (ii)      , a fact that is largely responsible for its (iii)      through the ages.

While there is nothing                 about the periodic disintegrations of the Chinese empire, its repeated resurrection within more or less the same boundaries clearly distinguishes China from other continental powers.

Surprisingly, although the textbooks are filled with pages of vocabulary and unnecessary detail, their treatment of some fundamentally important concepts is                 .

In the 1980s, the press release announcing the discovery of a new fundamental particle turned a once                 hypothesis of interest to no more than a few hundred physicists into an undisputed fact of global significance.