司机开动运煤机前应发出音响信号，确定()时方可起动。

多项选择题Some internet game producers lack sufficient understanding in ______,________,________. A. overseas players' habits B. cultural taboos C. the local legal systems D. overseas players' interests

单项选择题Listen to the words and repeat. Then tick the word that contains the same vowel as the word you hear. Each word will be read twice. (听单词。跟读单词。然后勾出包含相同的元音的单词选项。每个单词读两遍。) U3_4.mp3 A、zoo B、hen C、law D、good