.fbe {
    display: inline-block;
    height: 1em;
    width: 1em;
    margin: 0 .05em 0 .1em;
    vertical-align: -0.1em;
    background-repeat: no-repeat;
    background-position: center center;
    background-size: 1em 1em;
}

.fbe-test-tube {
    background-image: url("https://em-content.zobj.net/source/facebook/355/test-tube_1f9ea.png");
}

.fbe-fish {
    background-image: url("https://em-content.zobj.net/source/facebook/355/fish_1f41f.png");
}

.fbe-gear {
    background-image: url("https://em-content.zobj.net/source/facebook/355/gear_2699-fe0f.png");
}

.fbe-cow {
    background-image: url("https://em-content.zobj.net/source/facebook/355/cow_1f404.png");
}

.fbe-deciduous-tree {
    background-image: url("https://em-content.zobj.net/source/facebook/355/deciduous-tree_1f333.png");
}

.fbe-rock {
    background-image: url("https://em-content.zobj.net/source/facebook/355/rock_1faa8.png");
}

.fbe-bread {
    background-image: url("https://em-content.zobj.net/source/facebook/355/bread_1f35e.png");
}

.fbe-airplane {
    background-image: url("https://em-content.zobj.net/source/facebook/355/airplane_2708-fe0f.png");
}