He always had his camera ready whenever he traveled, just                  he saw something that would make a good picture.

in case

so that

for fear that

as if

考查连词。句意：每次旅行时，他总是把相机准备好，以防看到能拍出好照片的东西。A. in case 万一；B. so that 以便；C. for fear that 唯恐；D. as if 好像。前面的 “他总是把相机准备好” 跟后面的 “看到能拍出好照片的东西” 是假设条件关系，应用in case (倘若，以防万一)。故选A。