课堂上介绍的，景区常见的青铜雕像，是采用哪种方法制作的？
A. 焊接
B. 砂型铸造
C. 压铸
D. 失蜡铸造
查看答案
青铜是铜中含有哪个主要元素？
A. Zn
B. Sn
C. Mg
D. Fe
医用外科口罩的主要原材料是
A. 聚氯乙烯
B. 聚乙烯
C. 聚丙烯
D. 聚碳酸酯
The biggest advantage of inertial navigation is ____.
A. Highly accurate navigation
B. No accumulated error
Completely independent navigation
D. Good flight control capability
Which one of the world's four largest satellite navigation systems has the short message communication function? ____.
A. GPS navigation system
B. GLONASS navigation system
C. Beidou Navigation Satellite System
D. Galileo satellite navigation system
微信支付 
支付宝支付