皮皮学，免费搜题
登录
搜题
【单选题】
若在区间内 ， 则曲线 在此区间上（ ）A.
沿 轴正向上升并且是凹的
B.
沿 轴正向下降并且是凹的
C.
沿 轴正向上升并且是凸的
D.
沿 轴正向下降并且是凸的
拍照语音搜题，微信中搜索"皮皮学"使用
参考答案：
参考解析：
知识点：
皮皮学刷刷变学霸
举一反三
【单选题】(课文理解U5textA P15-16) Which sentence can describe the situation of workers without special or valuable skills according to paragraphs 15-16?
A.
It is not difficult for trade unions to organize workers online.
B.
Workers can not afford to pay for their pension pots and their health-care coverage has also decreased.
C.
Workers on a contract basis working through online platforms also have the right to gain a minimum wage.
D.
Because of automation, the demand for low-skill labors is increasing.