The coffe isn't strong __ to keep us awake

1.The coffe isn't strong ........................................ to keep us awake.

a. that             b. enough                   c. so                            d. as

2. He used to ................................. soccer when he was a child.

a. play             b. plays                       c. playing                   d. played

3. Do you mind ................................. the floor for me?

a. clean           b. to clean                  c. cleaned                   d. cleaning

4. Would you mind .................................. I smork here?

a. when           b. where                     c. if                             d. that

5. It's difficult ...................................... English well.

a. learnt          b. learning                  c. learn                       d. to learn