2 . The health security systems of many countries are undergoing considerable ______.

A．reservation

B．transformation

C．distinction

D．submission

3 . We have entered into an age _______ dreams have the best chance of coming true.

A．which

B．what

C．when

D．that

4 . ___________in 1931, the Empire State Building, the highest skyscraper until 1954, inspired the imagination of the world.

A．Having completed	B．Being completed
C．Completed	D．Completing

5 . The days are gone ______ physical strength was all you needed to make a living.

A．when

B．that

C．where

D．which

6 . The student completed this experiment to make come true ______ Professor Joseph had said.

A．that

B．what

C．when

D．where

7 . _____is known to all, China will be an _____and powerful country in 20 or 30 years or so.

A．That; advancing

B．This; advanced

C．As; advanced

D．It; advancing

9 . The musician along with his band members ________ ten performances in the last three months.

A．gives

B．has given

C．have given

D．give

10 . Because of COVD-19, days are gone ________ local 5-star hotels charged 5,000 yuan for one night.

A．if

B．when

C．which

D．since