A new system of control was __to overcome the defects in the firm's product.A installedB introduced

问题描述:

A new system of control was __to overcome the defects in the firm's product.
A installed
B introduced

应该是B.introduced
这题意思是说:一个新的控制系统被______,为了克服公司产品的瑕疵.
install是安装(电脑系统)的意思,可是这里的控制系统是抽象的东西,类似于公司管理一样的,而不是电脑系统.
所以应该用introduce,有引进的意思.