正确答案: B

much less than

题目：According to the passage, we can infer that the pole piece diameter must be tooth height.

解析：B

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举一反三的答案和解析：

[单选题]_____ of the controllable pitch propeller enables the blades to be moved to change the pitch angle

An internal mechanism

[单选题]海上待救时，艇筏集结相互间间距为：

20～30米

[单选题]()期间应检查管系、阀门是否有泄漏;透气系统是否处于设定状态;未装货舱也应检查，防止阀门开错或泄漏。

开始装货

[单选题]锚泊中从事疏浚作业的船舶，在白天应显示＿＿＿＿。

球、菱形、球垂直三个号型