何时

hé shí cái néng liǎo jiě dào qíng kuàng

何时才能了解到情况？

When will the information be made available ?

kē xué jiā bù què dìng gāi bìng dú hé shí chū xiàn

科学家不确定该病毒何时出现。

Scientists are unsure when the virus appeared.

tā men hé shí néng zuò chū jué dìng

他们何时能作出决定？

When will they come to a decision ?