Science lessons in most Welsh schools are good but assessment isn't robust enough, according to school inspectors.
Estyn also says sometimes, in primary schools, teachers pass on their science misunderstandings to pupils.
The Welsh Government welcomes the report which it says is broadly positive.
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Fine and dry at first but becoming largely cloudy with outbreaks of rain or drizzle.
First Minister Carwyn Jones says Wales must not get a bad deal in Brexit negotiations. He was speaking at meeting of British-Irish Council.
Isolated showers may last into the late evening, but a dry night.