What is seen in the middle of March and April that can’t be seen at the beginning or end of either month?​

The letter "R".

a-he encouraged islamic schools to introduce greek texts.

d-he invited greek scholars to teach their texts to the locals.

explanation:

the transmission of the greek classics to latin western europe during the middle ages was a key factor in the development of intellectual life in western europe.[1] interest in greek texts and their availability was scarce in the latin west during the earlier middle ages, but as traffic to the east increased so did western scholarship.

mark brainliest and have a great day!

b) ab

explanation: