不定项选择
所有的曲线曲面是不可展开的。
单项选择题 根据2018年中国人健康大数据显示,中国人患病人数最多的疾病是?
单项选择题 A.对B.错
问答题 1.What is the probable relationship between the two speakers? A、They are classmates. B、They are colleagues C、They are brothers D、They are professor and student