The top 20 most promising crypto assets in 2025 include BTC, ETH, SOL, etc., mainly covering multiple tracks such as public chains, Layer 2, AI, DeFi and gaming. 1.BTC continues to lead the market with its digital yellow metallicity and popularization of ETFs; 2.ETH consolidates the ecosystem due to its position and upgrade of smart contract platforms; 3.SOL stands out with high-performance public chains and developer communities; 4.LINK is the leader in oracle connecting real data; 5.RNDR builds decentralized GPU network service AI needs; 6.IMX focuses on Web3 games to provide a zero-gas-free environment; 7.ARB leads with mature Layer 2 technology and huge DeFi ecosystem; 8.MATIC has become the value layer of Ethereum through multi-chain evolution

The core difference between USDC, DAI and TUSD lies in the issuance mechanism, collateral assets and risk characteristics. 1. USDC is a centralized stablecoin issued by Circle and is collateralized by cash and short-term treasury bonds. Its advantages are compliance and transparent, strong liquidity, and high stability, but there is a risk of centralized review and single point failure; 2. DAI is a decentralized stablecoin, generated through the MakerDAO protocol, and the collateral is a crypto asset. It has the advantages of anti-censorship, transparency on chain, and permission-free, but it also faces systemic risks, dependence on centralized assets and complexity issues; 3. TUSD is a centralized stablecoin, emphasizing real-time on-chain reserve proof, providing higher frequency transparency verification, but has a small market share and weak liquidity. The three are collateral types and decentralization

The operating system is the basic software for managing hardware resources, running programs, and providing user interaction interfaces. It coordinates the relationship between hardware and software and is responsible for memory allocation, device scheduling, file management and multitasking. Common systems include Windows (suitable for office and gaming), macOS (Apple devices, suitable for creative work), Linux (open source, suitable for developers), and Android/iOS (mobile device system). The choice of ordinary users depends on the usage scenario, such as software compatibility, security and customization requirements. How to view system information: Use winver command for Windows, click on the machine for macOS, use terminal commands for Linux, and find the phone in settings. The operating system is the underlying tool for daily use,

In C, the POD (PlainOldData) type refers to a type with a simple structure and compatible with C language data processing. It needs to meet two conditions: it has ordinary copy semantics, which can be copied by memcpy; it has a standard layout and the memory structure is predictable. Specific requirements include: all non-static members are public, no user-defined constructors or destructors, no virtual functions or base classes, and all non-static members themselves are PODs. For example structPoint{intx;inty;} is POD. Its uses include binary I/O, C interoperability, performance optimization, etc. You can check whether the type is POD through std::is_pod, but it is recommended to use std::is_trivia after C 11.

In C, there are three main ways to pass functions as parameters: using function pointers, std::function and Lambda expressions, and template generics. 1. Function pointers are the most basic method, suitable for simple scenarios or C interface compatible, but poor readability; 2. Std::function combined with Lambda expressions is a recommended method in modern C, supporting a variety of callable objects and being type-safe; 3. Template generic methods are the most flexible, suitable for library code or general logic, but may increase the compilation time and code volume. Lambdas that capture the context must be passed through std::function or template and cannot be converted directly into function pointers.

In C, the mutable keyword is used to allow the object to be modified, even if the object is declared as const. Its core purpose is to maintain the logical constants of the object while allowing internal state changes, which are commonly found in cache, debug counters and thread synchronization primitives. When using it, mutable must be placed before the data member in the class definition, and it only applies to data members rather than global or local variables. In best practice, abuse should be avoided, concurrent synchronization should be paid attention to, and external behavior should be ensured. For example, std::shared_ptr uses mutable to manage reference counting to achieve thread safety and const correctness.

Kevin O'Leary highlights AI's transformative impact on reducing customer acquisition costs, reshaping investment strategies, and the US-China tech rivalry.

The key to an abstract class is that it contains at least one pure virtual function. When a pure virtual function is declared in the class (such as virtualvoiddoSomething()=0;), the class becomes an abstract class and cannot directly instantiate the object, but polymorphism can be realized through pointers or references; if the derived class does not implement all pure virtual functions, it will also remain an abstract class. Abstract classes are often used to define interfaces or shared behaviors, such as designing Shape classes in drawing applications and implementing the draw() method by derived classes such as Circle and Rectangle. Scenarios using abstract classes include: designing base classes that should not be instantiated directly, forcing multiple related classes to follow a unified interface, providing default behavior, and requiring subclasses to supplement details. In addition, C