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1·Many plants self-pollinate, but most orchids need help to reproduce.

许多植物自传花粉，但绝大多数兰花需要外界的帮助。

2·Second, the reproductive parts of the wheat plant are close together, so wheat tends to self-pollinate.

第二，小麦植株上的繁殖部位离得很近，所以小麦更倾向于自花授粉。

3·Because the research was done on plants, some skeptical of the findings thought it came from cross-pollination even though the plants self-pollinate.

由于研究对象是植物，有人怀疑这是交叉传粉的结果(即便这些植物是自花传粉)。

4·Because the research was done on plants, some skeptical of the findings thought it came from cross-pollination even though the plants self - pollinate.

由于研究对象是植物，有人怀疑这是交叉传粉的结果(即便这些植物是自花传粉)。