A:b电极的质量不变
B:a电极是该装置的负极
C:a电极上发生氧化反应
D:电子由b电极经溶液流向a电极
cooked , was , tired , visited, washed , cleaned , in , goes , told , next
My mother____busy last weekend . She____my grandma on Saturday m orning . They ____noodle together____the evening , she ____the clothes . She often____to the park, but she____my bedroom last Su nday. In the a fternoon , she went shopping . After supper , she ____stories for me .She was very ____last weekend . So I will help my mother do housework ____ weekend.
观察量筒中液面刻度时,要使视线与液面相平,量筒水银面是凸形的,观察时要( )