锡降落(tin parachute)
锡降落(tin parachute)
相关考题:
Because of the high loads the bearing material is a tin-aluminum(锡-铝) alloy bonded to a steel shell. The crosshead pin is highly polished to a______.A.flat surfaceB.mirror finishC.sloping(倾斜的) surfaceD.inclined(倾向的) surface
单选题The color of rockets,shells,or rocket parachute flares used to indicate that the vessel is in distress and requires immediate assistance is().AwhiteBgreenCredDyellow