pp-1-64 pp-1-68 2道PP的语法

ＸＩＸＩ，请大家指教～～：）

１．Lactose, a sugar present in milk, is one of simple sugars uesd in food preparations of infants.

为社么Ｂ是错的啊？应该咋改呢？此题争论过，有B不错说法，此时present is adj.。但大多数倾向于向B改为presenting。

２．Ｔhe Mississppi riverboat, which evoloved from simpler steamship of the early 1800's became the dominant form of passenger transport on Mississppi River

B哪里错了呢？可数单数名词不能单独出现，这是一个常见又很trick的考点

Lactose, a sugar present in milk, is one of simple sugars uesd in food preparations of infants.

C.  "one of several simple sugars"

"present" is fine here.  See this from M-W:

Main Entry: ³pres·ent
Pronunciation: 'pre-z^&nt
Function: adjective
Etymology: Middle English, from Old French, from Latin praesent-, praesens, from present participle of praeesse to be before one, from prae- pre- + esse to be -- more at IS1 : now existing or in progress
2 a : being in view or at hand b : existing in something mentioned or under consideration
3 : constituting the one actually involved, at hand, or being considered
4 : of, relating to, or constituting a verb tense that is expressive of present time or the time of speaking
5 obsolete : ATTENTIVE6 archaic : INSTANT, IMMEDIATE

Lactose, a sugar present in milk, is one of simple sugars uesd in food preparations of infants.

C.  "one of several simple sugars"

"present" is fine here.  See this from M-W:

Main Entry: ³pres·ent
Pronunciation: 'pre-z^&nt
Function: adjective
Etymology: Middle English, from Old French, from Latin praesent-, praesens, from present participle of praeesse to be before one, from prae- pre- + esse to be -- more at IS1 : now existing or in progress
2 a : being in view or at hand b : existing in something mentioned or under consideration
3 : constituting the one actually involved, at hand, or being considered
4 : of, relating to, or constituting a verb tense that is expressive of present time or the time of speaking
5 obsolete : ATTENTIVE6 archaic : INSTANT, IMMEDIATE