When did your brother begin to show hisinterest in medicine.—It was a Saturday _____ he noticed hisclassmate experimenting on a frog in the lab.

Look! The young girl is dressing up _______ an old woman ________ a black coat.

It is difficult to judge whether what he said_________

.—His father ______an actor , didn’t he —Yes, he did.

Where’s my baseball— ________under the bed.