It's our d___ to help the poor

It's our d___ to help the poor It's the doctor's d___ to save the patients. Look!This ia our students' d___.It's big and clean. Let's have a d___ about where to have our vacation. It's()to()()our classroom. It's easy to be good once ,but d___ all the time It's d___ for the children to swim alone in the river. It is d___ to climb the tree These are our r___ for d___ it.填写单词` Do you know Mexico?It is to the s____ part of USA.It's not a d___ country. I think you can do it,it's not d___ It's time to build our life it's our duty to protect our environment/是什么意思请问 we shall try our best to hel the people=we shal ()()()t help people It's d___ at nine o'clock in the evening. It's d___ ait nine o'clock in the evening. Don't go out ai night.It's d___. It is d___ for me to run in the playground.