“Do you thinkIshould attend the lecture” she asked me

Mr Bush is on time foreverything. How____ it be thmust

He made another wonderful discovery, _______ of great importance to science.

It was the drug，not the disease，that killed the boy.——He would be still alive today if he________ that drug.

There is ______ American boy in our class and ______ boy can speak good Chinese .