Answer:
1.Subject line: _____________ Supply of Suffocation Warning Bags
2. Opening sentence: ____________ We acknowledge the receipt of your request, dated April 4, 2021, for the supply of Suffocation Warning Bags.
Step-by-step explanation:
A business letter requires the use of a suitable subject line to summarize the topic of the correspondence. It enables the recipient to clearly and quickly understand the topic. The opening sentence should fully make reference to the subject with an acknowledgement of the inquiry earlier received from the recipient.