Sentences are grammatically correct and make sense.
In the first one means:
We have as much pens as they do.
Second means:
They are as tall as us.
"tan" is the equivalent in English for "as much". The concordance is well done in both cases.
Answer:
What island are we talking about?
Explanation:
Por el cambio climático que ocurre. Las hojas mueren durante el otoño y reviven (o nacen nuevas) en el otoño.
