请教语法问题

whxgmat

1. to develop more precise population forecasts, farmers would have to know a lot more than they do now about the social and economic determinants of fertility.

这是正确答案。为什么这里要用would have to呢？ 我自己选的答案是have to

2. A combination of poems and short fiction, Cheis Brown's Cane has been called one of the four best novels ever written by a African American - the others being Richard Charles's Native Daughter and Rick Allison's invisible Woman .

这是正确答案。
划线部分为什么用a  African American 而不是African Americans（题目不是说是4个最棒的作品吗？而根据破折号后面内容，这四个作品的作者不是一个人。）
另外，这里的being 算不算笨拙结构呢？
这里的破折号是对作家进行详细说明。 但是，破折号后面内容能不能说明前文提到的作品呢？（比如破折号后面是including XX作品 by 某某人 and XX 作品 by 某某人。）

3. 这题正确的句子是这样的：
Although she had been known as a real legislator first in the New York and later in the United States House of Representatives, Blanca Jordan did not become a nationally renowned figure until 1962, when she participated in the hearings on the impeachment of president Martin Nixon, which were televised across the whole nation.
划线部分的尾端 这个which 指代的是什么呢？为什么用复数were 而不是was？

Joehe2010

1. 这题应该是那个scientist would have to know more那题的变体吧，
用would have to是虚拟，说明他们现在还没有，句子补完应该是If farmers wanted to develop more precise population forecast, farmers would have to
主要考阅读理解了

2. 这条题又是另外一条雷同的变体，原题如下。
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
OA 是 E
这里破折号的意思就是指作品的，所里立即排除ACD
因为前文是JT'C，所以后面E比B更加平衡

a African American的意思是每一本小说都是一个非裔美国人写的，不是多人合作。
例句：all people have one heart, 2 arms and 2 legs.

3. which是指hearings因为harings是复数，所以后面要用were不是was

whxgmat

谢谢joehe的解答。