1 . He arrived in New York in 2019, ________, some time later, he became a writer.

A．where

B．when

C．that

D．which

2 . Tu Youyou went to Hainan, _______malaria was more common to study malaria patients.(用适当的词填空)

3 . Robinson was left on an isolated island, ________ he stayed for as long as twenty-eight years.

A．where

B．which

C．that

D．when

4 . Mark Zuckerberg is the founder of the site Facebook, you can have a look at each other’s pictures.

A．where

B．which

C．when

D．as