21.1: for note 5, what is fibre-reinforced materials? for examples?
22.3: in the second paragragh, how to understand the sentence beginning with" The socket-outlet-----"?
22.10: for the second paragragh, how to understand the term "trip-free"?
22.18: for note 2, what are the materials which are imcompatible to each other when they are used to make terminals?for examples?
24.2: for the third dashed item, how to understand the term" that can be reset by a soldering operation"?
25.11: what's the difference between lead-tin soldering and tin-soldering?can we treat them as the same in regard to the safety of this clause?
25.16: how to understand the eighth dashed item of type X attachments?
26.10: how to understand the term " screwless terminals"?
29.1: in the last paragragh, how to understand the sentence"Apertures are assumed to be covered by a piece of flat metal"? and why so?
29.1.1 How to understand the second paragragh beginning with" The clearance at the terminals----"?
29.1.4: how to understand the term " crossover points"?
29.2: how to understand Note 1?
Table 18: how to understand Note 1?
30.1: for note 1, what is "coil formers"?
