在生活中,往往会看到水中的鱼非常活跃,但离开水面一段时间就会死去。对此最合适的解释是[ ]
A.生物影响环境
B.生物适应环境
C.生物改变环境
D.生物依赖环境
答案:D
I have ________ French. What about you?
A.many difficulties to learn
B.a few troubles in learning
C.quite a little difficulty to learn
D.a great deal of trouble learning
闪蒸罐的目的是通过闪蒸分离出甘醇吸收的烃类气体。