insert 1 marker in the middle st.

How would the previous sentence be correctly capitalized?
Answer: Insert 1 marker in the middle st.
the download still requires validation before the package can be downloaded to the local system.

How would the previous sentence be correctly capitalized?
Answer: The download still requires validation before the package can be downloaded to the local system.
this modification of the kdv equation resulted in new phenomena.

How would the previous sentence be correctly capitalized?
Answer: This modification of the KdV equation resulted in new phenomena.
before buying a vacuum cleaner electrolux zeo 5410 essensio specify all your options, equipment, appearance and warranty from the seller. please note that we are not engaged in the sale and manufacture warranty.

How would the previous sentence be correctly capitalized?
Answer: Before buying a vacuum cleaner Electrolux ZEO 5410 Essensio specify all your options, equipment, appearance and warranty from the seller. Please note that we are not engaged in the sale and manufacture warranty.