The Smiths______ the Summer Palace three times.
A. have gone to
B. have been in
C. have been to
D. have gone into
成人大量血胸，出血量多( )
A. ＞300ml
B. ＞500ml
C. ＞1000ml
D. ＞1500ml
E. ＞2000ml
What guarantees the exchange of audio and video attachments
A. Higher-end applications.
B. Four megabytes' e-mail storage.
C. Sixty-two megabytes' e-mail storage.
D. 250 megabytes' e-mail storag
导致事故的物理性危险和有害因素不包括( )。
A. 设备、设施缺陷
B. 防护缺陷
C. 辨识功能缺陷
D. 明火
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