In a producer/consumer relationship, when a consumer finds the buffer empty or finds that the previous data has already been read, the consumer should call __________.

Twitter currently has more than 500 million users who generate more than ________ million tweets each day

Fill in the blank(s) with correct word

The three basic protocols developed for the ARPANET were ______, ______, and ______.

Fill in the blank(s) with the appropriate word(s).