医务人员每天紧密观察病人的情况。

Yīwù rényuán měitiān jǐnmì guānchá bìngrén de qíngkuàng.

Medical staff closely monitor patients’ conditions every day.

我观察到他的表情，我认为他在说谎。

Wǒ guānchá dào tāde biǎoqíng, wǒ rènwéi tā zài shuōhuǎng.

I observed his expression and I think he was lying.

我喜欢观察大自然中的变化。

Wǒ xǐhuān guānchá dà zìrán zhōng de biànhuà.

I enjoy observing the changes in nature.