单选题 Helen is tired of watching her son ____ struggling through school, so she hired a tutor to help him.

单选题 He felt an sense of guilt for the death of the boy in the accident.

单选题 3.He went into the burning house _______to save the boy.

单选题 We may learn ________by three methods: by reflection, by imitation, and by experience.

单选题 Good quality training helps motivate staff and make businesses more _____.

单选题 2.He expects that he will find a good job after ________.

单选题 The trapped miners were, thinking that they might not be rescued.

单选题 1.He was declared _________of any crimes by the court.