急性气管-支气管炎的主要病变是()。
A.气管壁炎症
B.细支气管炎症
C.气管上皮细胞坏死
D.气管-支气管黏膜的急性炎症
E.支气管与肺泡的炎症
参考答案:D
立式车床适用于加工哪些类型的工件?
It’s 8 o’clock. My mother is reading a book. My sister and I _____.
A.is doing my homework
B.am doing my homework
C.is doing our homework
D.are doing our homework