一批零件，师傅要12天加工完，而徒弟比师傅要多加工4天。师傅每天比徒弟多加工5个。这批零件有多少个？
5×12÷4×（12+4）=240（个）
山药的功效是（）
A.健脾燥湿
B.养血安神
C.补肾涩精
D.益卫固表
E.升阳固表
It has been announced recently that all the schools ________ not have the students attend school if the
students have high temperatures.[ ]
A．need
B．shall
C．could
D．ought to
