1 . He is my __________ critic as well as my toughest competitor; he has sped up the process of my growth as and helped me find the key to success.

A．severest

B．toughest

C．roughest

D．hardest

2 . When weighing Thomas Jefferson’s legacy, one must consider, ______, his promotion of democratic principles, despite his ownership of slaves.

A．once and for all

B．in all

C．after all

D．above all

3 . The researcher’s use of real-world examples and case studies effectively ________ the complex concepts presented in the paper.

A．articulates

B．clarifies

C．illustrates

D．simplifies

4 . The repairman assured the homeowner that the issue with the boiler had been fixed ________.

A．permanently

B．temporarily

C．severely

D．gradually

5 . The company’s reputation for quality and reliability was built over many years of ________ high standards in all its products and services.

A．confirming

B．continuing

C．maintaining

D．performing

6 . As they face the threat of ________, the rapid decline in the population of certain species is a major concern for environmentalists.

A．expansion

B．growth

C．continuation

D．extinction

7 . Despite the promising economic data, experts are concerned about the ________ rate of unemployment.

A．exciting

B．surprising

C．alarming

D．stabilizing