.sme {
    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;
}

.sme-test-tube {
    background-image: url("https://em-content.zobj.net/source/samsung/380/test-tube_1f9ea.png");
}

.sme-fish {
    background-image: url("https://em-content.zobj.net/source/samsung/380/fish_1f41f.png");
}

.sme-gear {
    background-image: url("https://em-content.zobj.net/source/samsung/380/gear_2699-fe0f.png");
}

.sme-cow {
    background-image: url("https://em-content.zobj.net/source/samsung/380/cow_1f404.png");
}

.sme-deciduous-tree {
    background-image: url("https://em-content.zobj.net/source/samsung/380/deciduous-tree_1f333.png");
}

.sme-rock {
    background-image: url("https://em-content.zobj.net/source/samsung/380/rock_1faa8.png");
}

.sme-bread {
    background-image: url("https://em-content.zobj.net/source/samsung/380/bread_1f35e.png");
}

.sme-airplane {
    background-image: url("https://em-content.zobj.net/source/samsung/380/airplane_2708-fe0f.png");
}