There are some flowers that can only be pollinated by the humming birds.

有些花只能靠蜂鸟授粉。

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Three times a year Prof Thomson compared the fruiting rate of flowers that were left to be pollinated naturally, or given extra doses of pollen by hand.

汤姆森教授每年三次比较有待自然授粉或需人工授粉花的结实率。

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Side-by-side orchids can be pollinated by the same bee, which keeps the pollens distinct, but each orchid species will co-exist with a unique nutrient-supplying fungus.

紧挨着生长的兰花能被同一个蜜蜂传播花粉，而蜜蜂不会混淆它们的花粉。但是每一种兰花只会跟唯一一种提供养分的真菌形成共生关系。

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For example, in order to maintain the highest level of genetic purity, distinct varieties of self-pollinated crops such as wheat, rice, soybeans and barley need to be separated by at least 60 feet.

FORBES: Magazine Article