下列句中加点字的意义和用法，判断正确的一项是①生而知之者 ②困而不学，民斯为下矣 ③十室之邑 ④不如丘之好学也

My mother often tells me ______ the teachers carefully

It’s clever _____you to help me work out the difficult math problem. Thanks!— You are welcome. Now it’s easier _______you to understand it.

The train arrives in Liverpool at 10 p.m. tonight .The plane I would like to take from there _______by then.

It was because I was caught in thetraffic jam ________ I came to school late this morning.