[讨论][求助]几道语法题求教!

fernandochang

求教大虾解释! 谢谢!

1-89. {Prehistoric} villagers {tended to} work harder, suffer {from} more diseases, and eat {the} poorer diet than nomadic hunters did.
A)     WHY NOT B?
1-96. Cyclamates were introduced in the early 1950’s {as} alternative sweeteners {for} use {by individuals} who needed {reducing} their sugar intake for medical reasons.
A)     WHY NOT C?
1-100. Iron {is} one of the basic {element} of {which} the world {is made}.
A):B    WHY NOT D?
1-116. The {layers of} an elephant’s tusk are deposited {from} the pulp, {yet} that the innermost layer is the {newest}.
A):C     WHY NOT B?
1-131. {As sweeteners}, there is very {small} difference between honey and sucrose, {although} the former does contain minimal {quantities} of vitamins, minerals, and amino acids.
A):B   WHY NOT A?

xiang1jp

1-89. D "the poorer" means " poor persons" as noun not adj., here need "poorer diet"
B "tend to do" is correct.

1-100. B "elements",  "one of + plural form of noun" is a key point of ETS.
D is a complete sentence with which.

1-131. B "little". difference is a abstract noun.  

bradzwz

关于need to be done or need doing字典中说读可以，
为何这儿need doing 不行？