A:反应前后分子总数不变
B:甲分子中氮、氢原子个数比为3:1
C:甲,乙量物质反应的质量比为17:40
D:但元素的化合价在反应前后没有变化
A
It's a beautiful day in summer. There are many people on the beach. Mrs Guo and her two sons are on the beach, too. Look! Mrs Guo is swimming in the sea. She can swim fast. What are her sons doing? They are playing volleyball on the beach. There's a man under the umbrella. He's reading a book. Look! A little girl is collecting shells on the beach. She's very happy.
阅读下列材料,回答问题。
材料一:吾等对于袁世凯深加敬爱,愿此次革命之效果得有完全巩固之政府,与各外国公平交际,并保全内地治安之美满情形,使在中国之商务进步,此种政府,吾等将于外交上竭力相助。
——1911年11月15日英国外交部致驻华大使电文
材料二:袁世凯得到孙中山的保证以后,威逼清帝退位。1912年2月12日,宣统帝下诏退位。第二天,袁世凯通电赞成共和。1912年3月,袁世凯在北京就任中华民国临时大总统。