[讨论][求助]几道语法题求教!

fernandochang

请教大虾解释! 谢谢!
2-22. Also called the painted cup, the Indian paintbrush gives forth tiny flowers that are mostly green, while___ brightly colored.
(A)its leaves     (B)it leaves being     (C)are its leaves     (D)its leaves are
A)    WHY NOT A?
2-52. If volcanoes erupt explosively and cast fluid lava into the air, _____, dispersed by the wind, gives rise ot particles of various sizes.
(A)the lava     (B)and lava     (C)when lava     (D)which lava is
A):A     WHY NOT D?
2-65. Photographer Edward Steichen constantly {experimented new} techniques and materials {in} his quest {to have} photography accepted {as} a creative art.
A):A     WHY NOT D?
2-76. In art, caricature is a pictorial {representation which} the physical features {of} a person {or object} have been grossly exaggerated for {comic effect}.
A):A     WHY NOT B?

bradzwz

2-22 while后面要跟整个句子
2-52 缺主语
2-65 experimented with new, 好像as在该错中没有错的(参考)
2-76 which代词，指代前面的句子中的某部分，在后面句子中充当成分。但此题后面的句子是一个被动句主谓宾齐全，所以用in which指状语。