EventListener em um link a

var click = document.getElementsByClassName("test");

click.addEventListener("click",show_hide(),false);
function show_hide(){
    

    for(var i=0;i<document.getElementsByClassName("go").length;i++){

        if(click.display=="none"){
                click.style.display= "block";

        }else{
                click.style.display ="none";
        }

    }
    
}

.descida{
    
width: 100%;
    height: 50px;

}
.descida ul{
    
    
    background-color: white;
    list-style: none;
    position: relative;
    padding-left: 0px;
}
.click{
    background-color:#333;
    display: block;
    list-style: none;


}

.descida ul li a{
    color: white;
}
.descida ul ul{
    color: black;   
    position: absolute;
    /*visibility: hidden;*/
    background-color: white;

}




.go li a{

    padding: 3px 20px;
    clear: both;
    font-weight: 400;
    /*display: list-item;*/
    display: none;
    line-height: 1.42857143;
    text-decoration: none;
    
}

<div class="descida">

    <ul>
        <li class="menu">

            <a class="test" href="#">Apache Software Foundation
            </a>
        </li>

        <ul class="go">

            <li>
                <a href="#">Apache Homepage</a>
            </li>
            <li>
                <a href="#">License</a>
            </li>
            <li>
                <a href="#">Sponsorship</a>
            </li>
            <li>
                <a href="#">Thanks</a>
            </li>
            <li>
                <a href="#">Sercurity</a>

            </li>
        </ul>
    </ul>
</div>