题目

---Have you read this book? ---Yes. But that one is         worth reading. I suggest you read it. A．well   B．best   C．more D．better 答案：D如图所示，A、B、C三点都在匀强电场中，已知AC⊥BC，∠ABC=60°，BC=20 cm。把一个电荷量q=10-5 C的正电荷从A移到B，电场力做功为零，从B移到C，电场力做功为-1.73×10-3 J，则该匀强电场的场强大小和方向是 [     ]A．865 V/m，垂直AC向左 B．865 V/m．垂直AC向右 C．1 000 V/m，垂直AB斜向上D．1 000 V/m，垂直AB斜向下