题干
The flowers _________sweet in the botanic garden attract the visitors to the beauty of nature．
A：to smell
B：smelling
C：smelt
D：to be smelt
答案(点此获取答案解析）
B
A：to smell
B：smelling
C：smelt
D：to be smelt
。恒容时，温度升高，H2浓度减小。下列说法正确的是