【题目】Emergency line operators must always calm and make sure that they get all the information they need to send help .
A. grow B. appear C. become D. stay
在线课程【答案】D
【解析】
句意：急诊热线的接线员们必须一直保持冷静，并确保得到他们所需的所有信息以便派出救助。A项grow和C项become都表示“变化”，与always意义不符合；appear作系动词，表示“好像，似乎”之意，不符合题意。系动词stay意为“保持”，符合题意。