Natural gas is already the principal source of heat in half of American households.
天然气已经是美国大半家庭的主要热能来源。
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One of its principal findings shows that more than a quarter of all students (28%) receive less financial parental support than in previous years, while nearly half (46%) receive none.
Ofsted found that about half the schools and nursery providers visited used low attainment and relatively slow progress as their principal indicators of SEN.