please add_“s”after_“r”.-OK,i understand. A an an Ba an C an

I have orange it's orange A：a‘an B：an’an C：an’/ D：/'an 选哪个 There's 'u' and 'r' in the word 'umbrella'.A:a;an B:an;an C: An, there is -------"r" and -----"u"in the word ruler A an,an Ba She's got____"A"_____maths again A.an...with B.an...for C.an 选择填空：1.I have__aunt and__uncle a.an;an b.an;a c.a;an d.a;a I have（ ）uncle and （ ） aunt.A.an,an B.a,a C.a,an D.an,a He is an OK Give me ( ) orange,please.I want ( ) big orange.A.an,an B.a, 1.What's this? It"s（）orange. It's（）orange A.an,an B.an,/ C./ please take a s() tom said to an old man ___ elephant is ___ useful animal.A.An;an B.An;a C.Thn;an D.