根据课文内容填空。 The students are (1) the playground. They (2) (3) a PF lesson. (4) is their teacher. He is (5) orders and the students are trying (6) (7) the orders. 1. (8) (9)____ a line. Let's (10)____ some exercise. 2. (11) __ your (12) together. Jump (13) and (14) ten (15) . 3. Put your hands (16) your head and turn (17) and (18) ten times. 4. Lie (19)_ your (20) and lift (21) your left leg and (22) it (23)_ your right hand.