Present perfect or present perfect continous

Since January, we................... part in three discussions on higher education.

• have taken

• have been taking

I'm sorry I'm so late! How long ................you .............for me?

• have ............waited

• have .....been waiting

How many academic courses.................you...............?

• have ....been attending

• have.......attended

I...........my research paper since October and I am trying my best to finish and submit it to my professor next week.

• have written

• have been writing

Alice...............in Viet Nam during her gap year and will return to the United States in December.

• has been travelling

• has travelled

The graduate students started arriving at four o'clock. They are still arriving.

= The graduate students ............... since four o'clock.

Rewrite the sentences, using the present perfect or the present perfect continuous:

They visited this college in 2009, 2012 and 2014. ( three times)

Rewrite the sentences, using the present perfect or the present perfect continuous:

She started her research project last month. She's still doing it.

I started learning how to play the piano eight months ago. I'm still learning it.

= I .................to play the piano over the last eight months

• have been learning

• have learnt

The graduate students started arriving at four o'clock. They are all in the lecture hall.

= The graduate students .................at the lecture hall.

• have been arriving

• have all arrived