Sự nhiễm vi rút sốt rét có thể gây ra nhiều triệu chứng khác nhau

inflection of malaria parasites may result a wide variety of symptoms

The acting is of variable quality (= some of it is good and some of it is bad).

an official piece of paper on which a doctor writes the type of medicine you should have, and which enables you to get it from a chemist

The origins of the story are lost in the mists of time (= forgotten because it happened such a long time ago).

(figurative) She gazed at the scene through a mist of tears.