— ______ is the Changjiang River in China, do you know?— Yes, it's about 6,380 kilometers long.
A:How many
B:How wide
C:How long
D:How much
把一杯饱和NaCl溶液加热蒸发掉一些水分后,冷却至原来的温度,保持不变的是( )
How kind you are! You always do what you can __________ others.