按发生机制,双吸气见于哪类呼吸困难
A.肺源性
B.心源性
C.中毒性
D.呼吸中枢性
E.精神性
参考答案:D
人类巨细胞病毒在哪种细胞内增殖()。
A.神经细胞
B.杯状细胞
C.成纤维细胞
D.色素上皮细胞
E.生殖细胞
The environment in our hometown is getting worse and worse. So many trees ________. [ ]
A. are planting
B. should be planted
C. should plant
D. will plant