蔬菜和水果是人体获得（）的主要食品原料。
A、维生素
B、糖类
C、脂肪
D、蛋白质
参考答案：A
—Do I have to finish the project in two days?
—Yes. In fact, I hope you can finish it . [ ]
A. quick .
B. as quicker as possible
C. as soon as possible
D. very quick
带式逆止器的输送机在何种情况下制动才安全可靠？又在何种情况下应设置制动装置？
