驻波中，任意两个振动质元的相位差或者为0，或者为。
A、正确
B、错误

单项选择题Before any month-end adjustments are made, the net income of ABC company is 12,000 rental at the beginning of the year for a whole year. After adjusting entries are made for the items listed above, ABC companys net income is ____ A、0. C、$124,000. D、None of the above.

单项选择题A、从 到 ，电场力做功最大。 B、从 到 ，电场力做功最大。 C、从 到 ，电场力做功最大。 D、从 到、、各点，电场力做功相等。