导致心肌炎最主要的病原是()
A.病毒
B.细菌
C.支原体
D.寄生虫
E.立克次体
参考答案:A
采用土钉加固一破碎岩质边坡,其中某根土钉有效锚固长度L=4.0m,该土钉计算承受拉力E为188kN,锚孔直径d=108mm,锚孔壁对砂浆的极限剪应力τ=0.25MPa,钉材与砂浆间黏结力τg=2.0MPa,钉材直径db=32mm,该土钉抗拨安全系数最接近下列()选项中的值。
A.K=0.55
B.K=1.80
C.K=2.37
D.K=4.28
The car is environmentally friendly because it uses electricity instead of gas. _____, it is less expensive.
A.Besides
B.However
C.Instead
D.Therefore