Made changes to ch02.asciidoc

ch02.asciidoc

@@ -232,12 +232,11 @@ In <<user-stories>>, we introduced Jing, a computer engineering student in Shang
 
 ((("mining","transactions in blocks")))((("transactions","mining in blocks")))A transaction transmitted across the network is not verified until it becomes part of the global distributed ledger, the block chain. Every 10 minutes on average, miners generate a new block that contains all the transactions since the last block. New transactions are constantly flowing into the network from user wallets and other applications. As these are seen by the bitcoin network nodes, they get added to a temporary pool of unverified transactions maintained by each node. As miners build a new block, they add unverified transactions from this pool to a new block and then attempt to solve a very hard problem (a.k.a., proof of work) to prove the validity of that new block. The process of mining is explained in detail in <<mining>>.
 
-Transactions are added to the new block, prioritized by the highest-fee transactions first and a few other criteria. Each miner starts the process of mining a new block of transactions as soon as they receive the previous block from the network, knowing they have lost that previous round of competition. They immediately create a new block, fill it with transactions and the fingerprint of the previous block, and start calculating the Proof-Of-Work for the new block. Each miner includes a special transaction in his block, one that pays his own bitcoin address a reward of newly created bitcoins (currently 25 BTC per block). If he finds a solution that makes that block valid, he "wins" this reward because his successful block is added to the global blockchain and the reward transaction he included becomes spendable. Jing, who participates in a mining pool, has set up his software to create new blocks that assign the reward to a pool address. From there, a share of the reward is distributed to Jing and other miners in proportion to the amount of work they contributed in the last round. 
+Transactions are added to the new block, prioritized by the highest-fee transactions first and a few other criteria. Each miner starts the process of mining a new block of transactions as soon as he receives the previous block from the network, knowing he has lost that previous round of competition. He immediately creates a new block, fills it with transactions and the fingerprint of the previous block, and starts calculating the proof of work for the new block. Each miner includes a special transaction in his block, one that pays his own bitcoin address a reward of newly created bitcoins (currently 25 BTC per block). If he finds a solution that makes that block valid, he "wins" this reward because his successful block is added to the global block chain and the reward transaction he included becomes spendable. Jing, who participates in a mining pool, has set up his software to create new blocks that assign the reward to a pool address. From there, a share of the reward is distributed to Jing and other miners in proportion to the amount of work they contributed in the last round. 
 
 Alice's transaction was picked up by the network and included in the pool of unverified transactions. Because it had sufficient fees, it was included in a new block generated by Jing's mining pool. Approximately five minutes after the transaction was first transmitted by Alice's wallet, Jing's ASIC miner found a solution for the block and published it as block #277316, containing 419 other transactions. Jing's ASIC miner published the new block on the bitcoin network, where other miners validated it and started the race to generate the next block. 
 
-You can see the block that includes Alice's transaction here:
-https://blockchain.info/block-height/277316.
+You can see the block that includes https://blockchain.info/block-height/277316[Alice's transaction].
 
 A few minutes later, a new block, #277317, is mined by another miner. Because this new block is based on the previous block (#277316) that contained Alice's transaction, it added even more computation on top of that block, thereby strengthening the trust in those transactions. The block containing Alice's transaction is counted as one "confirmation" of that transaction. Each block mined on top of the one containing the transaction is an additional confirmation. As the blocks pile on top of each other, it becomes exponentially harder to reverse the transaction, thereby making it more and more trusted by the network.