1 . Volunteers in China, _______ are playing an increasingly important role in many fields, are actively participating in the battle against COVID-19 at present.

A．which

B．that

C．who

D．where

2 . Most players of the basketball team, _______ had tried their best to play the game, were sleeping soundly.

A．which

B．who

C．where

D．that

3 . The manager offered the job to Helen, _____was the most suitable for the position.

A．he believed	B．who he believed
C．he believed she	D．whom he believed

4 . My uncle,   ________ has lived most of his life abroad is going to return to his hometown.

A．whom

B．who

C．which

D．that

5 . The Shenzhou-12 crew, ________ had spent 3 months aboard the space station, returned to the earth just in time for the Mid-Autumn Festival on September 17.

A．whose

B．which

C．that

D．who

6 . Jules Vern, ________ was best known for his adventure stories, is often called the "Father of Science Fiction".

A．that

B．which

C．who

D．whom