one of 复数名词 that + 单数还是复数形式

最近做题碰到一个疑惑，请大家帮帮忙，快考试了，很急啊！

one of 复数名词that + 单数还是复数动词阿？

我这里有几个例子，不过我被搞混淆了

With its abundance of noun inflections, Icelandic is one of several Germanic languages that is compact when written but can lengthen considerably when translated into English.

(A) is compact when written but can lengthen considerably when translated into English

(B) are compact when they are written, but they can lengthen considerably when they are translated in English

(C) is compact when written but can lengthen considerably when being translated into English

(D) are compact when written but can lengthen considerably in English translation（D）

(E) is compact when it is written but can lengthen considerably when translated in English

用复数了

A mixture of poems and short fiction, Jean Toomer’s Cane has been called one of the three best novels ever written by Black Americans—the others being Richard Wright, author of Native Son, and Ralph Ellison, author of Invisible Man.

A.      Black Americans—the others being Richard Wright, author of Native Son, and Ralph Ellison, author of Invisible Man

B.      Black Americans—including Native Son by Richard Wright and Invisible Man by Ralph Ellison

C.      a Black American—including Richard Wright, author of Native Son, and Ralph Ellison, author of Invisible Man

D.      a Black American—the others being Richard Wright, author of Native Son, and Ralph Ellison, author of Invisible Man

E.       a Black American—the others being Richard Wright’s Native Son and Ralph Ellison’s Invisible Man

答案：E 用单数

A South American bird that forages for winged termites and other small insects while swinging upside down form the foliage of tall trees, the graveteiro belongs to the ovenbird family, a group of New World tropical birds that includes more than 230 species and that are represented in virtually every kind of habitat.

A.      graveteiro belongs to the ovenbird family, a group of New World
            tropical birds that includes more than 230 species and that are

B.      graveteiro belongs to the ovenbird family, a group of New World
            tropical birds that includes more than 230 species and  is

C.      graveteiro belongs to the ovenbird family, a group of New World
            tropical birds that include more than 230 species and  is

D.      graveteiro, which belongs to the ovenbird family, a group of New World tropical birds that includes more than 230 species and that are

E.       graveteiro, which belongs to the ovenbird family, a group of New World tropical birds that includes more than 230 species and is

答案：B 用的单数。

请教，拜托！！

这几道题MM不能单看形式阿，要看题目的意思。

第二道题，完全不能用你说的one of +复数名词 来套的，和第一个题目的结构差别很远啊。

one of 复数名词 that,that后面如果是定于从句修饰复数名词的话，肯定应该用复数的。