What does just blows hot and cold mean?

[blowy]

English Idioms and Expressions, Intermediate level

ESL/EFL Test #15 "Expressions with cold", question 8

You never really know where you are with her as she just blows hot and cold.

(a) keeps talking
(b) keeps taking things
(c) keeps changing her mood
(d) keeps testing

English Idioms and Expressions, Intermediate level

ESL/EFL Test #15 "Expressions with cold", answer 8

You never really know where you are with her as she keeps changing her mood.

Correct answer: (c) keeps changing her mood
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just blows hot and cold means keeps changing her mood

[Mister Micawber]

Yes
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Native English teacher at Mister Micawber's