女性生殖器结核的常见传播途径是（）
A.直接蔓延
B.经血行传播
C.经淋巴传播
D.垂直传播
E.医源性感染
参考答案：B
预拌混凝土交货检验的试样应随机从同一运输车中抽取，混凝土试样应在卸料量的（）之间采取。
A.1/3～2/3
B.1/4～3/4
C.1/5～4/5
D.1/2～2/3
The young pioneers kept on working in the fields ________ they felt tired and thirsty.[ ]
A. but
B. or
C. even though
D. since
