患者女性，68岁，缺失，余留牙正常，拟行可摘局部义齿修复，设计正型卡环，后腭杆连接，支架在制作时应该考虑

若采用钴铬合金铸造该腭杆，正确的是（）

A.若该腭杆长度不足40mm时，最厚部约为1mm

B.若该腭杆长度不足40mm时，最厚部约为1.3mm

C.若该腭杆长度超过40mm时，最厚部约为1mm

D.若该腭杆长度超过40mm时，最厚部约为1.3mm

E.若该腭杆长度超过40mm时，杆长每增加10mm，厚度增加0.02mm

Fire in an engine compartment is best extinguished with carbon dioxide gas (CO₂) and by（）.

A.closing the compartment except for the ventilators

B.completely closing the compartment

C.leaving the compartment open to the air

D.increasing the air flow to the compartment by blowers