4. a. Where does Billy usually draw pictures?
b. Where is Billy drawing flowers...
c. Where did Billy draw animals...
d. Where will Billy draw birds...
e. Where has Billy drawn his pet...
5. a. Which of your friends has swum...
b. Which of your friends is bathing...
c. Which of your friends swam in the pond...
d. Which of your friends will bath...
e. Which of your friends has swum in the lake....
6. a. Do the children build toy....
b. Are the children building...
c. Did the children build...
d. Will the children build....
e. Have the children built....