Water pollution influences the look of our city and even worse, it _______ our health.
A:does good to
B:points to
C:does harm to
D:is helpful to
⑴is (过去式)____
⑵could not (缩写形式)____
⑶saw (原形)____
⑷give (过去式)____
一个小数扩大3倍后得到的数比原数大 7.2,原来的小数是( )