The fundamental cause is unknown, though a number of predisposing conditions are recognized.

虽然研究者们已经发现了很多相关的发病因素，但其发病机制仍不清楚。

youdao

The fundamental cause is unknown, though a number of predisposing conditions are recognized.

虽然研究者们已经发现了很多相关的发病因素，但其发病机制仍不清楚。

youdao