نمایش نتیجه 18671 تا 18673 از 18673 نتیجه یافت شده برای O:
n: a formation that contains holes or cracks large enough to allow cement to flow into the formation instead of up along the annulus outside of the casing.
The bit with only one cone,the rotate speed of cone is low ,which can adapt to big change of rotate speed.
a class of surfactant with both positive and negative charges.
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