A. Assume that you are given both the preorder and postorder traversal of some binary tree t. Prove that this information, taken together, is not necessarily sufficient to reconstruct t uniquely, even if each value in t occurs only once. b. Now, assume that you have the preorder and inorder traversals of a tree (given below). Construct the corresponding binary tree and determine its postorder traversal.

Preorder Traversal: D C B A F E
Inorder Traversal: C A B D E F

What did i do wrong with this const discord = require('discord.js'); var bot = new discord.client(); const token = 'ntm3mjcxmtu1mjg3ote2ntq2.dyogew.dpfiwfpuifzuzvifop-csuxasnm' const prefix = "! " bot.registry.registergroup('simple', 'simple'); bot.registry.registerdefaults(); bot.registry. + '/commands'); bot.on('message', message => { if(message.content == 'hi! ') { message.channel.send ('@everyone sup, how is @everyone day going'); } if(message.content == 'h3lp') { message.channel.send ('dose not have any commands yet'); } bot.on('ready', function() { console.log("ready") }); bot.login(token);

Which two technologies support the building of single-page applications?

Dereck works for long hours on his computer.  he frequently experiences physical strain by the end of the day because he does not follow an important rule of ergonomics with respect to the use of keyboards.  which of the following actions of dereck could lead to physical strain? a.  placing the keyboard exactly in front of him while typingb.  keeping hands and wrists straight while typingc.  using wrist pads throughout the dayd.  pounding at the keys on the keyboard while typinge.  resting his hands on the keyboard when he is not typing