问题
单项选择题
天然色素的颜色受到自身结构、温度、pH等因素的影响，下面颜色不受pH影响的一类色素是：（）
A、花色苷
B、类黄酮类
C、甜菜色素
D、类胡萝卜素
答案
参考答案：C
搜题请搜索小程序“爱下问搜题”
天然色素的颜色受到自身结构、温度、pH等因素的影响，下面颜色不受pH影响的一类色素是：（）
A、花色苷
B、类黄酮类
C、甜菜色素
D、类胡萝卜素
参考答案：C
Passage Three
How do the militants justify their kidnapping of oil workers
A．They argue that oil resources in the Niger Delta region are exhausting.
B．They are not satisfied with the generous pay of the oil workers.
C．They claim that the Niger Delta region is off limit to foreign oil companies.
D．They see their action as protest against the uneven distribution of the oil wealth.