【单选题】—I've been to the space museum. —______ It's really great. [ ]
【单选题】精馏塔中由塔顶向下的第n-1,n,n+1层塔板,其气相组成关系为()
【单选题】—It’s dangerous to swim here. Look at the sign. —Oh, I _______ notice it. Thanks for telling me.
【单选题】人眼看到的光称为可见光,其波长范围为( )。
【单选题】—Would you like to go to the People's Park with me on May Day? —I'd love to, ______ I'm afraid I have no time. [ ]
【单选题】精馏塔中由塔顶向下的第n-1,n,n+1层塔板,其气相组成关系为( )。
【单选题】Mum, I’ve cut my finger. It’s bleeding! --- _______.