下列物质中，可以用于钢铁除锈的是（ ）
①盐酸；②氢氧化钠；③硫酸；④食盐．
A：③④
B：②④
C：①③
D：①②
She always does very well in the English exams. But she can understand VOA Special English.
The university started some new language programs to _____ the country’s Silk Road Economic Belt.
