元代园林史的特点是什么？
参考答案：
造园艺术处于滞缓状态和低潮。造园活动不多，造园实践和理论均无多大的建树。
—What can you see in the picture?
—I can see a farm. And there ______ a lot of animals on it. [ ]
A. is
B. are
C. will be
D. be
_____________ 的式子，叫做化学方程式。
