Ilona: Sorry I'm late.
Emma: It's OK. … I haven't been waiting… (I / not / wait) long.
What (1)................. (you / do)?
Nelly: I've been with Mrs. King. (2)................. (she / help) me with my English.
Nelly: Your English is very good. You don't need lessons, surely. How long (3)........................ (you / study) English?
Ilona: Er, eight years now. But my accent wasn't so good before I came to England. (4).............. (I / try) to improve it. I think (5)..................... (it / get) better lately.
Nelly: Your accent is fine, Ilona. Honestly.

Правильное заполнение пропусков:

Ilona: Sorry I'm late.
Emma: It's OK. I haven't been waiting long. What have you been doing?
Nelly: I've been with Mrs. King. She has been helping me with my English.
Nelly: Your English is very good. You don't need lessons, surely. How long have you been studying English?
Ilona: Er, eight years now. But my accent wasn't so good before I came to England. I've been trying to improve it. I think it has been getting better lately.
Nelly: Your accent is fine, Ilona. Honestly.

Объяснение:

1. What have you been doing? — используется Present Perfect Continuous, потому что спрашивают, чем человек занимался до настоящего момента.

2. She has been helping — действие началось раньше и продолжалось некоторое время до момента разговора.

3. How long have you been studying English? — вопрос о длительности действия, которое началось в прошлом и продолжается сейчас.

4. I've been trying — попытки улучшить акцент происходят в течение некоторого времени.

5. It has been getting better — улучшение происходило постепенно в последнее время.