A:how long can I keep the books
B:how long I can keep the books
C:when should I return the books
D:when I should return the books
读一读,照样子组成词语。
例:万 一万 万里无云
冬____ ____ 齐____ ____ 百____ ____
利用计算器求值(结果精确到0.001):sin55°≈____ ;tan45°23′≈____ .
Our English teacher is very kind ________us.