The book took ten years of <u>thorough</u> research.

相关题目

• We shall take the treasure away to a <u> safe</u> place.
• She often <u> find fault with</u> my work.
• I simply gave in to him,and I've felt <u>regretted </u> it ever
• <u>In short </u>,I am going to live there myself.
• Who is the <u>head</u> of this delegation?