What the science teacher does and says       of great importance to college students.

________ of the land in that district _______ covered with trees and grass.

According to the recent regulation, it is required that any chemical plant that_______ along the river _______ to build a recycling center for the waste.

When the teacher asks him, he always ____.

(2013·高考江苏卷)Generally，students’ inner motivation with high expectations from others________essential to their development.