1.The e-commerce company is responsible for most online sales in China.
is responsible for负责
She is responsible for the determination of wage levels within this company.
她负责确定这家公司职员的工资标准 。
2.It is also involved in banking and other areas and has just been growing so dramatically that it now accounts for 80 percent of e-commerce in China.
account for(在数量、比例上)占
Together they account for less than five per cent of the population.
他们总共占不到总人口的5% 。