【单选题】—_____? —He is helpful. He's always ready to help anyone in need. [ ]
A.
How's your new friend like?
B.
What's your new friend like
C.
How do you like your new friend?
D.
What do you think your new friend
【单选题】在用生物素标记酶时,酶活性会降低的是( )
【单选题】You'd better have your hair()before going to your friend's wedding.
【单选题】Who's your best friend? [ ]
B.
She's my English teacher.
C.
Sarah is my best friend.
【单选题】下列各种模型元素中,不属于UML模型元素的是( )。