你想让别人打开书,你应该说 A. Open your book. B. Close your book.
The birds are singing the tree . A .on B. up C .in
What’s she ? A. do B. doing C. does
We had a picnic the park . A. in B. on C. with
We are looking the picture. A. of B. from C. at
The ducks are . A. swim B. swam C. swimming