21. Peter was so excited ___ he received an invitation from his friend to visit Chongqing.
A. where B. that C. why D. when
22. —Ann is in hospital.
—Oh, really? I ____ know. I ______ go and visit her.
A. don’t; am going to B. don’t; would C. don’t; will D. didn’t; will
23. The war made _______ impossible for the scientist to go on with his research.
A. him B. it C. this D. that
