As one of the youngest professors in the university, Mr. Brown is certainly on the （）of a brilliant career.

A．They will be sold at a very low price.
B．Their production process is complicated.
C．Purchase orders can be made through the Internet.
D．They have to be replaced every day.

A．net inhabitants should not let security. measures affect their joy of surfing the Internet
B．we should make full use of the Internet before security measures are strengthened
C．influential businessmen should give priority to the improvement of Net security
D．we should alert the most influential businessmen to the importance of security