胸外伤后,出现胸壁软化,是因为______
A.单根肋骨单处骨折B.相邻多根肋骨多处骨折C.单根肋骨多处骨折D.多根肋骨单处骨折E.胸骨骨折
参考答案:B
In China's countryside, villagers often have the same family name, but ________ not be closely related.
A.need
B.shall
C.must
D.may
卡钳是一种不能直接读出测量数值的间接量具。