The instantaneous center of velocity of two links that form a sliding pair is located at（）
A. Infinity point perpendicular to the direction of the guide line of the sliding pair
B. On the line perpendicular to the direction of the guide line of the sliding pair
C. In the middle of the guide line
D. At the contact point of the two links
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What are the main features of mechanisms（）
Assembly of man-made components
B. Determinate relative motions among different components
Can conduct work/energy conversion
D. Well designed shapes and structures
rènshi nǐ hěn gāoxìng 认识 你 很 高兴 means（）
A. Nice to meet you
B. You are very happy
C. See you soon
D. Good morning
jīnɡlǐ hǎo 经理 好 means（）
A. Hello teacher
B. Hello manager
C. Hello friend
D. Hello classmate
provides an explanation for the origin of mass（）
A. Higgs mechanism
B. Yang-Mills gauge theory
C. The general theory of relativity
D. The special theory of relativity
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