Yes, you can get USDT for free in the following 5 ways: 1. Participate in airdrop tasks on mainstream exchanges, such as registering and giving away, completing novice tasks, and inviting friends to get rewards; 2. Join the blockchain project community and obtain airdrops through Web3 social platform or Twitter/Discord interaction; 3. Participate in the "test network" activity, register the test chain address and simulate the use of DApp to get incentives; 4. Complete tasks on the cryptocurrency navigation platform to receive novice gift packages, participate in sign-in, lottery and other activities; 5. Interact with the content creation and community, and publish original content to obtain USDT rewards from the project party. At the same time, you need to pay attention to security risks, do not fill in private keys, do not believe in scams, and choose mainstream platforms to participate.

The role of Ethereum smart contract is to realize decentralized, automated and transparent protocol execution. Its core functions include: 1. As the core logic layer of DApp, it supports token issuance, DeFi, NFT and other functions; 2. Automatically execute contracts through code to reduce the risks of human intervention and fraud; 3. Build a DeFi ecosystem so that users can directly conduct financial operations such as lending and transactions; 4. Create and manage digital assets to ensure uniqueness and verifiability; 5. Improve the transparency and security of supply chain and identity verification; 6. Support DAO governance and realize decentralized decision-making.

The duration of the airdrop dividend is uncertain, but the LayerZero, StarkNet and ZK ecosystems still have long-term value. 1. LayerZero achieves cross-chain interoperability through lightweight protocols; 2. StarkNet provides efficient and low-cost Ethereum L2 expansion solutions based on ZK-STARKs technology; 3. ZK ecosystem (such as zkSync, Scroll, etc.) expands the application of zero-knowledge proof in scaling and privacy protection; 4. Participation methods include the use of bridging tools, interactive DApps, participating test networks, pledged assets, etc., aiming to experience the next generation of blockchain infrastructure in advance and strive for potential airdrop opportunities.

To identify fake altcoins, you need to start from six aspects. 1. Check and verify the background of the materials and project, including white papers, official websites, code open source addresses and team transparency; 2. Observe the online platform and give priority to mainstream exchanges; 3. Beware of high returns and people-pulling modes to avoid fund traps; 4. Analyze the contract code and token mechanism to check whether there are malicious functions; 5. Review community and media operations to identify false popularity; 6. Follow practical anti-fraud suggestions, such as not believing in recommendations or using professional wallets. The above steps can effectively avoid scams and protect asset security.

Is DAI suitable for long-term holding? The answer depends on individual needs and risk preferences. 1. DAI is a decentralized stablecoin, generated by excessive collateral for crypto assets, suitable for users who pursue censorship resistance and transparency; 2. Its stability is slightly inferior to USDC, and may experience slight deansal due to collateral fluctuations; 3. Applicable to lending, pledge and governance scenarios in the DeFi ecosystem; 4. Pay attention to the upgrade and governance risks of MakerDAO system. If you pursue high stability and compliance guarantees, it is recommended to choose USDC; if you attach importance to the concept of decentralization and actively participate in DeFi applications, DAI has long-term value. The combination of the two can also improve the security and flexibility of asset allocation.

The top ten popular digital currency trading platforms in the world include Binance, Ouyi OKX, gate.io, Huobi, KuCoin, Kraken, Bitfinex and Bitstamp. 1. Binance is known for its large trading volume, rich trading pairs, multi-trading mode, high security and user-friendly; 2. Ouyi OKX provides diversified derivatives, localized services, stable technology and Web3 layout; 3. gate.io has the advantages of strict project screening, many trading products, strong compliance, diverse financial products and simple interface; 4. Huobi has mainstream trading products, complete security guarantees, rich activities and localized operations; 5. KuCoin focuses on potential currencies, diversified trading tools, platform currency benefits and multi-language support; 6

The value of stablecoins is usually pegged to the US dollar 1:1, but it will fluctuate slightly due to factors such as market supply and demand, investor confidence and reserve assets. For example, USDT fell to $0.87 in 2018, and USDC fell to around $0.87 in 2023 due to the Silicon Valley banking crisis. The anchoring mechanism of stablecoins mainly includes: 1. fiat currency reserve type (such as USDT, USDC), which relies on the issuer's reserves; 2. cryptocurrency mortgage type (such as DAI), which maintains stability by over-collateralizing other cryptocurrencies; 3. Algorithmic stablecoins (such as UST), which relies on algorithms to adjust supply, but have higher risks. Common trading platforms recommendations include: 1. Binance, providing rich trading products and strong liquidity; 2. OKX,

DAI is suitable for users who attach importance to the concept of decentralization, actively participate in the DeFi ecosystem, need cross-chain asset liquidity, and pursue asset transparency and autonomy. 1. Supporters of the decentralization concept trust smart contracts and community governance; 2. DeFi users can be used for lending, pledge, and liquidity mining; 3. Cross-chain users can achieve flexible transfer of multi-chain assets; 4. Governance participants can influence system decisions through voting. Its main scenarios include decentralized lending, asset hedging, liquidity mining, cross-border payments and community governance. At the same time, it is necessary to pay attention to system risks, mortgage fluctuations risks and technical threshold issues.