Jackie Joyner-Kersee

(3.) Ms Joyner-Kersee practics many hours a day for the woman's heptathlon.

SPELLING: practices
CAPITALIZATION ok
PUNCTUATION Periods (with abbreviated titles)
GRAMMAR & USAGE Plurals (irregular plurals)

Ms. Joyner-Kersee practices many hours a day for the woman's heptathlon.

(4.) This contest consist of seven events, including running jumping and throwing.

SPELLING: ok
CAPITALIZATION ok
PUNCTUATION commas (for items in series)
GRAMMAR & USAGE Agreement (of subjects and verbs)

This contest consists of seven events, including running, jumping, and throwing.