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單項(xiàng)選擇題

An LWT anchor often has difficulty tripping in（）.

A.sand
B.soft soil
C.stiff clay
D.heterogeneous soil

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單項(xiàng)選擇題

An integral part of a blowout preventer that serves as the closing element on an open hole，and whose ends do not fit around the drill pipe but seal against each other and shut off the space below completely is the（）.

A.shear ram
B.blind ram
C.pipe ram
D.annular ram

單項(xiàng)選擇題

An example of a modern anchor which has a stock is a(n)（）.

A.articulated anchor
B.Flipper Delta anchor
C.Baldt anchor
D.Danforth anchor

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