Run-on sentences and punctuation

Which of the following sentences is punctuated correctly?

• Mary graduated in four years, but she didn't find a job immediately.

• It was a large, black, Labrador retriever.

• Mary who is my sister will be at the party too.

Which of the following sentences is punctuated correctly?

• No one expected her to buy a car, so we were quite surprised when we discovered that she had bought two.

• No one expected her to buy a car, so we were quite surprised, when we discovered that she had bought two.

• No one expected her to buy a car, so we were quite surprised when we discovered, that she had bought two.

Which sentence is a run-on sentence?

• I attended the conference last July I also was at the symposium in October. 

• I attended the conference last July, and I was at the symposium in October. 

• I attended the conference last July; I also was at the symposium in October. 

Which sentence is a run-on sentence?

• The results of the study were inconclusive, more research needs to be done on the topic.

• The results of the study were inconclusive, but more research needs to be done on the topic.

• The results of the study were inconclusive; however more research needs to be done on the topic.

Which sentence is punctuated right?

• Employee morale has a big impact on productivity, managers should evaluate the employee's emotional needs.

• Employee morale has a big impact on productivity, therefore managers should evaluate the employee's emotional needs.

• Employee morale has a big impact on productivity; therefore managers should evaluate the employee's emotional needs.

Fix this run-on sentence:

Judy leads a charmed life she never seems to have a serious accident.

• life, she

• life; she

• life: she

Fix this run-on sentence:

The airport is about to shut down because of the snow and if the plane doesn't land soon it will have to go on to Boston.

• snow, and

• snow; and

• snow. And

Which option does not fix this run-on sentence?

The show begins at 7:30 make sure you're there before 7:15.

• 7:30. Make

• 7:30, make

• 7:30; make

Fix this run-on sentence:

Throughout history money and religion were closely linked there was little distinction between government and religion.

• linked because there was

• linked, there was

• linked however there was

Which option does not fix this run-on sentence?

I love to write papers I would write one every day if I had the time.

• papers, I would write

• papers; I would write

• papers. I would write