这些小问题也许是更大危机的预兆。

Zhèxiē xiǎo wèntí yěxǔ shì gèng dà wēijī de yùzhào.

These small problems may be a sign of a bigger crisis.

天空突然变暗，像是要下大雨的预兆。

Tiānkōng tūrán biàn'àn, xiàng shì yào xià dàyǔ de yùzhào.

The sky suddenly turned dark, like a sign that it was going to rain heavily.