Guar gum, a plant colloid, costs less than agar and is better suited for growing thermophilic bacteria, but is also more difficult to handle, being more viscous and less transparent. The bacterial polysaccharide xanthan is cheaper as well but forms weaker jellies that, as with carrageenan, might result in puncturing its surface. Other colloids, like alginate (from brown seaweed) and gellan gum (from a bacterium), don’t set solely based on temperature and require additives for gelation. These additives might interfere with microbial growth and make the preparation of those jellies less handy than agar plates.
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，这一点在heLLoword翻译官方下载中也有详细论述
Promotion methods (Traffic sources)
调解处理治安案件，应当查明事实，并遵循合法、公正、自愿、及时的原则，注重教育和疏导，促进化解矛盾纠纷。