题目

 To make himself ____ he spoke clearly and slowly. A. understand     B. understood     C. understanding     D. to understand 答案：B把萝卜条放入浓盐水中将会发生的变化是（ ）A．细胞吸水，萝卜条变硬B．细胞吸水，萝卜条变软C．细胞失水，萝卜条变硬D．细胞失水，萝卜条变软