【单选题】若对心尖顶直动从动件盘形凸轮机构的推程压力角超过了许用值,在不改变从动件运动规律的情况下,可采用____措施进行改进。
【单选题】I prefer clothes which are made out of natural materials, ______cotton and wool.
【单选题】The MIT team had tried different materials before they studied natural silk in their research. 查看材料
【单选题】It is indicated that materials stronger than natural silk can be expected in the furore. 查看材料
【单选题】若对心尖顶直动从动件盘形凸轮机构的推程压力角超过许用值时,解决的措施是( )
【单选题】It can be inferred from the passage that________
A.
natural materials are safe in food processing
B.
chemicals are needed in food processing
C.
food poisoning can be kept under control
D.
food poisoning is out of control
【多选题】若对心尖顶直动从动件盘形凸轮机构的推程压力角超过许用值时,可采用 ____ 措施来解决。