Choose the best answer to complete the following sentences.Mathematics ______ my favourite subject.
A.is
B.has been
C.are
D.was

Choose the best answer to complete the following sentences.The writer and poet ______ going to preside over thi s morning.
A.are
B.is to
C.has been
D.is

Choose the best answer to complete the following sentences.The boy, along with his two companions, ______ the cherry tree now.
A.are spliting
B.has split
C.is spliting
D.have split

Choose the best answer to complete the following sentences.The number of students in this school ______ increasing now.
A.were
B.was
C.is
D.are

Choose the best answer to complete the following sentences.Neither the mother nor the children ______ aware of the danger.
A.was
B.were
C.has been
D.is

Choose the best answer to complete the following sentences.A large number of students in this college ______ Chinese fluently.
A.has spoken
B.speak
C.speaks
D.is speaking

Choose the best answer to complete the following sentences.What ______ you used in picking a winner in the contest of eloquence?
A.are the criterion
B.is the criteria
C.are the criterions
D.are the criteria

Choose the best answer to complete the following sentences.The quality of these videos ______ very good.
A.are not
B.were not
C.is not
D.have not been

By the time we started our work, he had explained everything clearly.
A.Before we had started our work, he explained everything clearly.
B.After we started our work, he had explained everything clearly.
C.We started our work before he had explained everything clearly.
D.After he had explained everything clearly, we started our work.

I did all my homework, and then I went out with my friends.
A.Before I did all my homework, I had gone out with my friends.
B.
C.Before I went out with my friends, I had done all my homework.
D.After I did all my homework, I went out with my friends.