题目

— What color is your coat?— It's ______ orange. It's ______ orange coat. A . an, / B . /, an C . a, an D . an, an 答案：B4．下列属于遗传病一组的是（　　）A．白化病、先天愚型、侏儒症B．白化病、色盲、先天愚型C．白喉、夜盲症、色盲D．坏血病、血吸虫病