在板式塔塔板中，（）的作用是使液体由上一层塔板流到下一层塔板。
A、降液管
B、入口堰
C、出口堰
D、浮阀孔
参考答案：A
His glasses, _____he was like a blind man, were broken.
A．with which
B．with it
C．without which
D．without it
Mike looks _______ than Paul, but they are of the same age. [ ]
A. youngest
B. the youngest
C. younger
D. very young
