Mark the correct variant to complete the sentence.
1 The window... by a couple of boys who were playing football,
A was broken
B is broken
С broke
D broken

2 They to my birthday party next month. A are be invited
B will be invited
C will be invite
D be invited

3 Two centuries ago computers....
A didn't were used
B weren't use
C were using
D weren't used

4 Credit cards ... out of plastic.
A is always made
B are always making
C are always maked
D are always made​