‍和小肠对葡萄糖的吸收方式一样，肾小管对葡萄糖的吸收也是继发式主动吸收​

A．x = function (a, b) {return a * b};
B．var x = function (a, b) {return a * b};
C．var x = function (a, b) {a * b}
D．var x = function {return a * b}