Hellen is fond of light music, _____ her brother is keen on rock and roll.

--Where is Hellen? I am looking for her. --_____ to Australia. She’s been there for three days.

I introduce you to my roommate, Hellen? A: Will B: Do C: Have D: Can

Hellen is fond of light music, _______ her brother is keen on rock and roll.（1.0分） A: when B: and C: while D: for

Hellen is fond of light music, _______ her brother is keen on rock and roll. A: when B: and C: while D: fo

Which sentences are complex sentences? A: Hellen put on his clothes and went out. B: You know that I hate war. C: The children argued over whether bats had wings. D: The essay that he wrote is excellent.

建立一个包含3个用户信息的用户名密码字典。[br][/br] 当用户输入用户名信息时，如果不存在该用户信息，则提示用户重新输入，直到用户输入的用户名存在为止。 然后，提示用户输入对应密码，如果用户输入密码不正确，提示用户重新输入，直到输入的密码正确为止。当用户密码输入正确后，提示登录成功。 [br][/br] 例如：建立的用户字典信息如下： accounts = {'Alice': '123456', 'Bill': '654321', 'Joe': '111222'} [br][/br] 预期测试结果诸如: Enter username: Hellen this username does not exist. please re-enter. Enter username: Joe Enter password: 111 password error, please re-enter. Enter password: 111222 you have successfully logged in.