Educationists across China are experimenting and________ new assessing systems appropriate to assess(评价) students’ performance in school.

Our physics teacher told us light _______ faster than sound.

It’s dangerous to walk across the street carelessly.— You’re right. We can’t be careful while crossing the street.

How could you ________ such a fantastic job when you have been out of work for months

Hi, Jean! You look unhappy. _________