Lesson 20 Christmas Tree一、给下列单词分类。 1. 2. 二、我会选。( )1. Let's__________.A. put up it B.put it up C. put up( )2. We put the lights_____________the tree.A.on B.at C.off( )3. He________to the zoo yesterday.A.go B.goes C.went( )4. My homework is___________.A.do B.did C.done( )5. I...