James and his team didn't finish the project; They did work hard * Similarly
However
Firstly

However

Explanation:

In English, However can be used to join two independences sentence into one compound sentence. These independences sentence generally in contrast/oppose to  one another.

1st. Sentence : James and his team didn't finish the project.

2nd. Sentence: They did work hard.

Working hard generally resulted in finishing the project. So, these two sentences basically in contrast with one another. Because of this, using 'however' to join the two sentences would be appropriate.

saving account is right

swahili is an extremely rich and complex civilization, a set of ethnic groups articulated by a language and a series of cultural elements that fuse the african traditions, islam and indian culture. this growth was largely a result of the indian ocean trading network that brought in not just man-made riches, but also religious ideas, specifically islam, which had a significant impact on the local culture. furthermore, the development of the swahili language gave a common cultural unity to the people.