220kV及以上变电工程作业人员上下时构架时必须使用何种安全防护用品？
参考答案：
攀登自锁器。
After taking part in several rounds of competition, the athlete won first prize.
A．eventually
B．occasionally
C．frequently
D．usually
妊娠期的妇女用药要特别慎重，尤其是怀孕（）
