Premium economy shell seats on Japan Airlines. Premium economy is a travel class offered on some airlines. Positioning in price, comfort, and amenities, this travel class is leveled between economy class and business class. In 1991, EVA Air was the first to introduce Evergreen Class and had since become the first airline to offer this class of service in the world.
This sentence has two independent clauses. They are connected by and with a comma before it. The and and the comma are correct. However, adding a comma after thus is not correct because it is an adverb; the comma after it is not necessary. If thus is used as a conjunctive adverb (without and), a semi-colon and a comma are necessary.
Use a comma to separate the elements in a series (three or more things), including the last two. He hit the ball, dropped the bat, and ran to first base.. You may have learned that the comma before the and is unnecessary, which is fine if you're in control of things.sing a comma between all the items in a series, including the last two, avoids this problem. This last commathe one between the word and and the preceding wordis often called the serial comma or the Oxford comma.