单项选择题 Because the tie bolts are so close to the crankshaft, some engines employ （）to hold the crankshaft main bearing cap in position instead of conventional studs and nuts.

单项选择题 To prevent excessive （） in the transverse girders, the tie bolts are positioned as close to the center of the crankshaft as possible.

单项选择题 The A-frames carry the crosshead guides and support the engine （）.