The main purpose of the piston oil scraper rings is to （）.
1、What is the main purpose of the passag
What is the main purpose of the passage?ATo show us the hidden beauty in our world.BTo warn us not to get lost in the fantasy wonderCTo argue against the misuse of the sense of wonderDTo discuss the influence of the world of make-believe
2、The main purpose of the text is to tel
The main purpose of the text is to tell parents ___________.A how to get along with a teenagerB how to respect a teenagerC how to understand a teenagerD how to help a teenager grow u
3、What is the main purpose of dunnage（）.
What is the main purpose of dunnage（）.ATo act as ballast for light vesselsBTo provide ventilation and drainage for cargoCTo secure the tarpaulins in placeDTo support weakened bulkhead
4、The main purpose of warming the parts
The main purpose of warming the parts of the main engine is （）Ato reduce heat stressBto reduce low temperature corrosionCto improve firing and starting performanceDfuel saving
5、The main purpose of the text is to ___
The main purpose of the text is to _______.A describe children’s thinkingBanswer some questions children haveCstress the importance of communicationDadvise parents to encourage their children
6、The purpose of a main switchboard circ
The purpose of a main switchboard circuit breakers reverse-power trip is to （）.Aprevent main circuit overloadBprotect the circuit breaker blowout coilCprevent alternator motorizationDprevent low voltage tripout