Need advice on simple past or present perfect, thx teachers! ^^

[Help Wanted]

Dear teachers,

It has been ages since I popped in for advice. Hope everything goes well here and i could see it's blooming. Keep up, teachers!
I just wondered if I should use simple past or present perfect in the following sentence. Please advise, thanks sooooo much.

Q1.
While we are waiting for Mum, let me show you the great pictures I ( took or have taken???) in Peru.

Q2.
Jane: Have you seen Sam? It's already 8:00p.m. and he's usually on time.
Ian: No, they (just called or have just called???) me. They have just missed a bus and are on their way.

Bunch of thx for advising, teachers. Help Wanted

[RonBee]

1. While we are waiting for Mum, let me show you the great pictures I took in Peru.

2.
Jane: Have you seen Sam? It's already 8:00p.m. and he's usually on time.
Ian: No, but they just called me. They are on their way. They missed a bus, which is why they will be late.

~R

[RonBee]

P.S. Assuming that you agree with the changes, tell me why they should be made.

[Help Wanted]

Thanks, teacher RonBee! However, I don't know why they should be made. Did you want me to explain? I am a little puzzled.

[RonBee]

Okay. Let's have a go at it.

While we are waiting for Mum, let me show you the great pictures I took in Peru.

The word "took" is not even a verb in that sentence. It is part of the noun phrase "the great pictures I took in Peru". (What kind of pictures are they? They are the citures I took in Peru.) It would be a verb in this sentence:

I took those pictures in Peru.

In any case, we only use past perfect when talking about something that occurred before another specific event.

Let's look at the other one.

Jane: Have you seen Sam? It's already 8:00p.m. and he's usually on time.
Ian: No, but they just called me. They are on their way. They missed a bus, which is why they will be late.

Jane is worried about Sam. He is late, which is not like him. She asks Ian if he knows anything. Ian replies that "they" have just called (very recently called) him and that they are on their way. (They should be arriving soon.) He adds that they will be late because they missed a bus. (They probably caught a later bus.)

There!

Is that helpful?