Any person who is sexually active should discuss his or her risk factors for stds/stis with a health care provider and ask about getting tested. Stds, also known as sexually transmitted infections (stis), are typically caused by bacteria or viruses and are passed from person to person during sexual contact with the penis, vagina, anus, or mouth. The symptoms of stds/stis vary between individuals, depending on the cause, and many people may not experience symptoms at all. · 在c++编程语言中，std::是一个非常重要的前缀，它指的是标准命名空间（standard namespace）。这个命名空间包含了c++标准库中的一部分基础功能，比如输入输出流对象`cin`和`cout`。在编写代码时，如果我们使用了`using namespace std;`声明，这意味着我们可以在代码中直接使用这些标准库的功能，而不需要. · how do health care providers diagnose a sexually transmitted disease (std) or sexually transmitted infection (sti)?
