完形填空： It was Children's Day yesterday, we 1 the park. Our teacher was 2 us. 3 many people there. Some Young Pioneers (少先队员) 4 near the river. 5 sang and danced. There were some 6 on the river. There was a hill 7 . Some boys 8 in the river. We sat under 9 apple tree with our teacher. We 10 on Children's Day yesterday. (     )1. A. went (     )2. A. to (     )3. A. Thosewere (     )4. A. are (     )5. A. They (     )6. A. hills (     )7. A. here (     )8. A. swim (     )9. A. a (     )10.A. liked B. went to B. from B. How B. was B. Them B. boats B. over B. swimming B. an B. enjoyed C. went for C. with C. Had C. were C. Their C. flowers C. over there C. swimmed C. / C. had great fun D. went in D. of D. There were D. did D. Theirs D. trees D. near D. swam D. the D. did