关于字符串s,以下说法中正确的是
A. s.lower()能够将字符串s修改为全是小写字母的形式
B. 如果 s.isalnum() 返回布尔值True就表示字符串s只由字符或数字构成
C. s.strip()能够删除字符串s中的所有空格
D. s.replace(s1, s2)能够将字符串中的子串s1修改为s2
假设字符串 s = "Welcome to Python",则 s.isalpha()返回
假设字符串 s = "3.3",则 s.isdigit()返回
Complete the sentences using the present continuous tense.1. The wind (blow) hard now.2. Where you (go) at the moment?3. We can feel that a big storm(come).4. I not (work) at the moment.5. Be quiet! The baby (sleep).