When I was young,I always read books at night.Which of the following is correct for the underlined word in the sentence?
---He is an honest person , so what he said is _______.
______ it is raining hard , they are still working in the field.
The houses in big cities are so expensive that I can’t __________ to buy one .
A smile costs _________, but gives so much. So we should learn to smile.
My mother often tells me ______ the teachers carefully