Question

There is (a/the/an)man at the door.He wants to see you.

You can buy(a/an/the)Octopus card at (a/an/the)MTR station.
The sun is(a/an/the)brightest thing in (a/an/the)world
I want to have (a/an/the)cat

Answer 1

There is 【a 】 man at the door.He wants to see you. 门口有个男的，他想见你。
一个: a / an, man是以辅音开始的单词，所以填： a

You can buy【 an 】Octopus card at 【 the 】MTR station.
The sun is【 the 】brightest thing in 【 the 】world
I want to have 【 a 】cat

祝你学习进步，更上一层楼！ (*^__^*)
不明白的再问哟，请及时采纳，多谢！

追问

You can buy(a/an/the)Octopus card at (a/an/the)MTR station.
The sun is(a/an/the)brightest thing in (a/an/the)world
I want to have (a/an/the)cat

追答

You can buy【an】Octopus card at 【the】MTR station.
The sun is【the】brightest thing in 【the】world
I want to have 【a】cat

Answer 2

a

追问

You can buy(a/an/the)Octopus card at (a/an/the)MTR station.
The sun is(a/an/the)brightest thing in (a/an/the)world
I want to have (a/an/the)cat

追答

a, the
the, the
a