Recharging a previously used cartridge-operated dry-chemical extinguisher is accomplished by（）.
A. authorized fire equipment servicing personnel only
B. replacing the propellent cartridge and refilling with powder
C. puncturing the cartridge seal after installation
D. recharging the cartridge and refilling it with powder
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佛焰花序属于肉穗花序，如马蹄莲的花序，外有一枚佛焰状的苞片。
A. 正确
B. 错误
某市公安局出入境管理部门为驻港部队干部罗某的妻子的签发《往来港澳通行证》及3个月多次探亲签注。
三相异步电动机转子的转速越低，电机的转差率越大，转子电动势频率越高。
A. 正确
B. 错误
The knot used to join two lines or two large hawsers for towing is called a（）.
A. square knot
B. carrick bend
C. sheet bend
D. bowline
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