Ann was very surprised to find the door unlocked. She remembered _________ it before she left.

     A. to lock                      B. having locked           C. to have locked          D. she locks

Tom looks so frightened and upset. He _________ something terrible.

     A. must experienced                                           B. can have experienced

     C. should have experienced                               D. must have experienced

The twins look so much alike that almost no one can _________ them _________ .

     A. take/apart                 B. tell/away                   C. tell/apart                   D. take/on

_________ , we tried our best to complete it.

     A. Thanks to the difficult homework                 B. Despite the homework was difficult

     C. Difficult as the homework was                     D. As though the homework was difficult

Of all the factors affecting agricultural yields, weather is the one _________ the most.

     A. that influences farmers                                  B. farmers that is influences

     C. why farmers influence it                                D. it influences farmers

Let’s begin our discussion now, _________ ?

     A. shall we                    B. will we                     C. don’t we                   D. won’t we

I will stand here and wait for you _________ you come back.

     A. because                    B. though                      C. so                              D. until

I’ve never really enjoyed going to the ballet ỏ the opre; they’re not really my _________ .

     A. piece of cake            B. sweets and candy     C. biscuit                       D. cup of tea

As I was walking along the street, I saw _________ $10 note on _________ pavement.

     A. a/the                         B. the/the                      C. a/a                             D. the/a

Extinction mean a situation _________ a plant, an animal or a way of life etc... stop existing.

     A. to which                   B. in which                   C. on which                   D. for which