Reflection of a beam of light on the diaphragm falls on a phototransistor.经膜片反射的光束照射到光敏管上.A beam of light produced by a laser can weld metals.激光器发生的光束可以焊接金属.A beam of light produced a laser can weld metals.激光器发生的光束可以焊接金属...
She saw Ellis, soberly dressed in a well-cut dark suit.她看见了埃利斯，他穿着一身裁剪合体的素净的黑西装。"You're a coward," Mark said very plainly and soberly.马克非常直率而严肃地说：“你是个懦夫。”"There's a new development," he said soberly.他表情严肃地说：“又有...