chalk是表示物质和抽象概念的不可数名词。有些名词一般只有单数形式，它们通常是表示物质和抽象概念的不可数名词，像:advice，baggage，bread，corn，clothing，equipment，education，fun，furniture，fMd，fruit，garbage，grass，happiness，homework，housework，humanity，information，knowledge，landscape，laughter，machinery，mankind，merchandise，money，music，nonsense，nature，population，progress，scenery，smoke，sweat，strength，traffic，thunder，ink，jewellery，damage，mail，work，soap，sugar，gold，chalk，cloth，anger，applause，cake ，chocoIate，poverty 等。例如:
I must seek the advice of a specialist in the matter of the transfer of property rights.
Headache is the most common disease of human.
I really get a lot of fun from reading in leisure time.
The population of Shanghai is very big.
