Why a design that doesn't fail initially fails after some time/use? identify at least 3 such mechanisms?

What ordering of tcp flags makes up the three-way handshake?

1. declare a constant named cents_per_pound and initialize with 25. 2. get the shipping weight from user input storing the weight into shipweightpounds. 3. using flat_fee_cents and cents_per_pound constants, assign shipcostcents with the cost of shipping a package weighing shipweightpounds.

What is one reason why indoor air pollution has become an increasing problem.