截至2014年10月底,我国现存艾滋病感染者和病人已达49.7万例,死亡15.4万例。据悉,在我国近一半艾滋病病毒感染者是在注射吸食毒品过程中被感染的。由此可见( )①感染了艾滋病后就一定会死亡②不吸食毒品就不会感染艾滋病③吸毒是感染艾滋病的高危行为④预防艾滋病需要远离毒品诱惑
--- Can you find me _______ symbol of China? --- ______ Great Wall.
Bob ________ with us together since he came to our school.
When I came into the teacher’s office, he ________ on the phone.
Tony decided to study abroad _______ he knew he would meet many difficulties.
--- We want to sit at the table near the window. --- I am sorry, but it _______ already.