下列不属于传统硅酸盐产品的是[ ]
A.玻璃
B.水泥
C.光导纤维
D.陶瓷
答案:C
This is such a wonderful film ______ we have never seen before.
A.that
B.as
C.which
D.what
实际制冷循环的节流过程是()
A、等焓过程
B、不可逆过程
C、升压过程
D、等干度过程