警察担心那对夫妇可能已经溺水了。

Police ___fear that the couple may have drowned.

据担心，多达两百名乘客可能已在坠机中丧生。

It is ___feared that as many as two hundred passengers may have died in the crash.

我们担心未来的几代人可能无法拥有像我们这样幸福的生活。

We ___fear that future generations may not have as happy lives as we do.