Review the details below.
.Dmitri Mendeleev arranged the elements in order of atomic weight and placed them in
rows and columns according to their physical and chemical properties.
.Dmitri Mendeleev created the periodic table for his book The Principles of Chemistry.
.Dmitri Mendeleev's periodic table contained only sixty elements, but the table was updated as other elements were discovered.

Choose the best topic sentence to introduce a paragraph containing these details.
1) In 1869, Russian chemist Dmitri Mendeleev invented the first periodic table of the elements.
2)Dmitri Mendeleev, a professor at the University of St. Petersburg, wrote a book called The Principles of Chemistry.
3)Dmitri Mendeleev was an important Russian chemist who was responsible for the Periodic Law, which states that the properties of elements recur at regular intervals when ordered by atomic weight.

When gregor, the protagonist in franz kafka’s the metamorphosis, transforms into a giant insect, his relationship with his family hits a low. however, in chapter 2, his relationship with his sister, grete, evolves as she becomes his sole caregiver. which of these excerpts talks about this new role for his sister? once during that long evening, the door on one side of the room was opened very slightly and hurriedly closed again; later on the door on the other side did the same; it seemed that someone needed to enter the room but thought better of it. gregor went and waited immediately by the door, resolved either to bring the timorous visitor into the room in some way or at least to find out who it was; but the door was opened no more that night and gregor waited in vain. the previous morning while the doors were locked everyone had wanted to get in there to him, but now, now that he had opened up one of the doors and the other had clearly been unlocked some time during the day, no-one came, and the keys were in the other sides. it was not until late at night that the gaslight in the living room was put out, and now it was easy to see that his parents and sister had stayed awake all that time, as they all could be distinctly heard as they went away together on tip-toe. it was clear that no-one would come into gregor's room any more until morning; that gave him plenty of time to think undisturbed about how he would have to re-arrange his life. for some reason, the tall, empty room where he was forced to remain made him feel uneasy as he lay there flat on the floor, even though he had been living in it for five years. hardly aware of what he was doing other than a slight feeling of shame, he hurried under the couch. it pressed down on his back a little, and he was no longer able to lift his head, but he nonetheless felt immediately at ease and his only regret was that his body was too broad to get it all underneath. … he spent the whole night there. some of the time he passed in a light sleep, although he frequently woke from it in alarm because of his hunger, and some of the time was spent in worries and vague hopes which, however, always led to the same conclusion: for the time being he must remain calm, he must show patience and the greatest consideration so that his family could bear the unpleasantness that he, in his present condition, was forced to impose on them. gregor soon had the opportunity to test the strength of his decisions, as early the next morning, almost before the night had ended, his sister, nearly fully dressed, opened the door from the front room and looked anxiously in. she did not see him straight away, but when she did notice him under the couch—he had to be somewhere, for god's sake, he couldn't have flown away—she was so shocked that she lost control of herself and slammed the door shut again from outside. … [h]is sister noticed the full dish immediately and looked at it and the few drops of milk splashed around it with some surprise. she immediately picked it up—using a rag, not her bare hands—and carried it out. gregor was extremely curious as to what she would bring in its place, imagining the wildest possibilities, but he never could have guessed what his sister, in her goodness, actually did bring. in order to test his taste, she brought him a whole selection of things, all spread out on an old newspaper. there were old, half-rotten vegetables; bones from the evening meal, covered in white sauce that had gone hard; a few raisins and almonds; some cheese that gregor had declared inedible two days before; a dry roll and some bread spread with butter and salt. as well as all that she had poured some water into the dish, which had probably been permanently set aside for gregor's use, and placed it beside them. then, out of consideration for gregor's feelings, as she knew that he would not eat in front of her, she hurried out again and even turned the key in the lock so that gregor would know he could make things as comfortable for himself as he liked. gregor's little legs whirred, at last he could eat.