Choose the underlined part that needs correcting

It was in 1971 that  transatlantic supersonic transportation became commercially availability

A. that

B. supersonic

C. became

D. availability

Choose the best answer to complete each of the following sentences

Britain has accused Russia ____ poisoning the ex-Russian spy Sergei Skripal and his daughter.

A. of

B. from

C. for

D. on

Kim loại là chất:

A. Dẫn điện 

B. Cách điện 

C. Vừa dẫn điện vừa cách điện 

D. Cả A, B, C đều sai