You should really smoking. It’s a terrible habit.

How careless Tom is! He forgot to remind his boss _____ the important meeting yesterday. 一 What is terrible! I am afraid his boss will never forgive him _____ his carelessness. [ ]

The great use of school education is not so much to teach you things ___ to teach you the art of learning.

In China, people walk _________ of the street.(街道) [ ]

Jack felt nervous when he found the physics problems ____ to work out.