Therearemanythingsinit.Thereisawhitepencil,awhiterulerandawhitepencilsharyeneri...Therearemanythingsinit.Thereisawhitepencil,awhiterulerandawhitepencilsharyenerinit.这两个句子中there是相同意思的吧?它

　　Therearemanythingsinit.Thereisawhitepencil,awhiterulerandawhitepencilsharyeneri...

　　Therearemanythingsinit.Thereisawhitepencil,awhiterulerandawhitepencilsharyenerinit.这两个句子中there是相同意思的吧?它在这类句式中是固定放句首的吗?第一句中大量东西用are,第二句中也有三样东西却用is,为什么呢?有什么规律吗?in在这里是在什么里面的意思吗?in+名词或代词在这类句式中是固定放在句末吗?