What _____ you doing ?A. are B.am C .is
We had a picnic Saturday .A.\ B. next C. last
.No! they in Beijing.A.isn′t B. weren′t C. wasn′t
Robots can. A. talk B. talking C. talked
you at home yesterday ?A. Is B. Were C. Was
it a big city then ?A. Was B. Were C. Are