题目

Roma Pass Kit (套装) enables both tourists and interested local residents the opportunity to benefit from various discounts and services that make it easier and cheaper to enjoy the sights of Rome． ． Free entry to the first 2 visited museums and / or archaeological sites of your choice．     ·  Concessionary(优惠的)ticket to all other museums and / or archaeological sites visited thereafter．     ·  Free use of the city’s public transport network．Valid until midnight of the third day inclusive that of the first validation for ATAC public transport within the ter用石墨电极电解CuCl2溶液（见图）。下列分析正确的是A．a端是直流电源的负极 B．通电使CuCl2发生电离 C．阳极上发生的反应：Cu2++2e-=Cu D．通电一段时间后，在阴极附近观察到黄绿色气体