目前我们翻砂厂一般采用（）及（）两种铸造方式
参考答案：砂型铸造；消失模铸造
This is the only one of the books on space ___.
A．that has been written
B．that have been written
C．which have been written
D．which has been written
下述哪项不是代谢酸中毒的血气特点()
A．SB降低
B．AB降低
C．BB降低
D．BE正值增大
E．PACO2代偿性降低
