Your Task. When indirectness or tact is required, use passive$-$voice verbs. Revise the following

active$-$voice sentences so that they are in the passive voice.

Example: Software engineers failed to patch bugs that spiraled into threats for users' data security.

Revision: Bugs were not patched and spiraled into threats for users' data security.

a$.$ Data scientists built the platform under rushed and less$-$than$-$ideal circumstances.

b$.$ The engineers failed to detect the flaws in the company's code thus compromising network security.

c$.$ The Theranos CEO defrauded investors.

d$.$ The airline refunds only the cost of the flight in the form of credit for future travel; it does not

include seat and business class upgrades.

e$.$ The crypto trading platform owes its $50$ biggest unsecured creditors more than $$3$ billion.