what‘s a plane 还是what's the plane?

问题描述:

what‘s a plane 还是what's the plane?
1.what()a plane?——It’s a machine that can fly
用a还是the?
2.Do you know who invited ()telephone?——Bell,It‘s()most useful invitation.用a还用the
麻烦把解析写出来
1.what’s()a plane?——It’s a machine that can fly
用a还是the?
第二题答案上用a,弄不懂诶

a 泛指,飞机是什么?
the 特指,第一步电话