However,            of web-based ④           in higher education is still encountered by challenges.
 
However, it is still challenging to adopt web-based learning and apply it in various ways in higher education. 

A．将10号存储单元的数，取出送到运算器的寄存器A中
B．将运算器中寄存器A的数，加上10号存储单元的数，结果保留在运算器的寄存器A中
C．将运算器的寄存器A中的数，保存到10号存储单元中
D．将运算器中寄存器A的数，乘以10号存储单元的数，结果保留在运算器的寄存器A中