all the student must follow their teacher's ( )while they are doing this experimentA.instructions B.instruction C.an instruction D.the instructions
问题描述：
all the student must follow their teacher's ( )while they are doing this experiment
A.instructions B.instruction C.an instruction D.the instructions
答
A
instruction是指示，已经有their teacher's作限定字，所以不加an或the，加上-s，因为老师不可能只发一个指令。希望我能帮助你解疑释惑。
答
我觉得是B。instruction是名词，不可数名词
答
A
没啥好解释,instructions 是指示,加个s是固定的
答
teacher不要偏s