病毒侵入寄主途径为（）。
A、微伤口
B、气孔
C、水孔
D、直接侵入
参考答案：A
The work was difficult, but Tom’s expression showed that he would finish it in time.
A．stubborn
B．determined
C．concerned
D．surprised
股骨颈头下型骨折最易并发（）
A.缺血性骨坏死
B.创伤性关节炎
C.创伤性骨化
D.坐骨神经损伤
E.关节僵硬
