几道纠结的语法题求解中！！！

重新编辑加入题目出处～～～xdf 蓝皮教材
P13.2.
At a recent session, the French government has decided that Paris needs a second, larger opera house to complement the famous Paris Opera. （B）
(A) has decided that Paris needs
(B) decided that Paris needs
(C) has decided that Paris will need
(D) decided that Paris has a need of
(E) has decided that Paris needed
这个题recent 是说最近的意思，应该用一般过去时，但是that后面的怎么冒出needs了？

P52.18
At the time of the Mexican agrarian revolution, the most radical faction, that of Zapata and his followers, proposed a return to communal ownership of land, to what had been a pre-Columbian form of ownership respected by the Spaniards. （A）
(A) land, to what had been a pre-Columbian form of ownership respected by the Spaniards
(B) land, a form of ownership of the pre-Columbians and respected by the Spaniards
(C) land, respected by the Spaniards and a pre-Columbian form of ownership
(D) land in which a pre-Columbian form of ownership was respected by the Spaniards
(E) land that had been a pre-Columbian form of ownership respected by the Spaniards
这个题就更纠结了，我看过许多都说是因为bcde存在修饰错误的问题，但是我想问，如果后面接定语从句，修饰的是中心词还是整个词，比如说，题中的communal ownership of land 后面接B选项的同位语从句，D选项的非限制性定语从句， E选项的限制性定语从句都是修饰land？为什么不是整个communal ownership of land？

P40.10
Because natural gas is composed mostly of methane, a simple hydrocarbon, vehicles powered by natural gas emit less of certain pollutants than the burning of gasoline or diesel fuel.    （E）
(A) less of certain pollutants than the burning of gasoline or diesel fuel
(B) fewer of certain pollutants than burning gasoline or diesel fuel do
(C) less of certain pollutants than gasoline or diesel fuel
(D) fewer of certain pollutants than does burning gasoline or diesel fuel
(E) less of certain pollutants than those burning gasoline or diesel fuel

这个题呢，根据比较对等原则，是对主语比较的，即vehicles 所以选E。我想问这个less of 和fewer of的用法。

P56.10
Several studies have found that the coronary patients who exercise most actively have half or less than half the chance of dying of a heart attack as those who are sedentary.  （E）
(A) have half or less than half the chance of dying of a heart attack as those who are sedentary
(B) have half the chance, or less, of dying of a heart attack than those who are sedentary do
(C) have half the chance that they will die of a heart attack, or less, than those who are sedentary do
(D) are at least fifty percent less likely to die of a heart attack as those who are sedentary
(E) are at least fifty percent less likely than those who are sedentary to die of a heart attack
这题我不知道B为什么不对了？

P94.11.
Affording strategic proximity to the Strait of Gibraltar, Morocco was also of interest to the French throughout the first half of the twentieth century because they assumed that if they did not hold it, their grip on Algeria was always insecure.  （B）
(A) if they did not hold it, their grip on Algeria was always insecure
(B) without it their grip on Algeria would never be secure
(C) their grip on Algeria was not ever secure if they did not hold it
(D) without that, they could never be secure about their grip on Algeria
(E) never would their grip on Algeria be secure if they did not hold it

这个题我纠结于B和E， A和C中的状语从句时态有问题，D中that指代很奇怪，但B和E呢，真不知道了，有人说E中结尾的it指代不清，我不太明白这里具体指代什么?
谢谢～～～～～～