铸造铝合金活塞，适宜的铸造方法是（）
A.金属型铸造
B.熔模铸造
C.砂型铸造
D.离心铸造
参考答案：A
Don’t make a noise! The latest sports news____on the radio. I want to listen to it.
A．is being broadcast
B．was broadcast
C．has broadcast
D．is broadcast
材料储备：
