How to select all elements whose ID starts and ends with specific strings?

The following CSS3 selector will do the job:

tr[id^="section_"][id$="_dummy"] {
    height: 200px;
}

The ^ denotes what the id should begin with.

The $ denotes what the id should end with.

id itself can be replaced with another attribute, such as href, when applied to (for example) <a>:

a[href^="http://www.example.com/product_"][href$="/about"] {
    background-color: red;
}