题目

某电场区域的电场线如图所示，a、b是其中一条电场线上的两点，下列说法中正确的是（  ）                                                                                                                                            A．  a点的场强方向一定沿着过a点的电场线向左    B．  a点的场强一定大于b点的场强    C．  正电荷在a点受到的电场力一定小于它在b点受到的电Though ____ to see the strangers, the housewife gave them a big smile and said hello. A．surprising                             B．to be surprised C．surprised                             D．having surprised