The rules are too (rigid) to allow for human error.

A. inflexible

B. general

C. complex

D. direct

This species has nearly (died out) because its habitat is being destroyed.

A. turned dead

B. passed by

C. carried away

D. become extinct

The contract between the two companies will (expire) soon.

A. shorten

B. end

C. start

D. resume

Three world-class tennis players came to (content) for this title.

A. argue

B. claim

C. wish

D. compete

The methods of communication used during the war were (primitive).

A. simple

B. reliable

C. effective

D. alternative