Read the following text and answer the questions.

Dear students grade X,

On behalf of the school committee, we would like to inform you that Mrs. Marcia Jonas has decided to retire this summer after 20 years of faithful service. It was tough to find a replacement for Mrs. Marcia Jonas. Nevertheless, we are really delighted to find Ms. Naseed Hibda.

Ms. Naseed Hibda obtained a Masters in Science & Technology from Macquarie University. She has spent 7 years in teaching high school students before joining us. She enjoys an excellent rapport with students, parents and colleagues, which explains all the appreciation certificates and awards on her desk. Ms. Naseed Hibda has a keen creative interest.

She came first in the International Science Competition in Geneva. Thanks to her assistance, we expect to take part in the next Olympiad. We just can't wait to start the year with Ms. Naseed Hilda.

Sincerely,
Wilson Richard
Principal

"... this summer after 20 years of faithful service."

What does the underlined word mean?