坝垛险情的抢护原则是什么？
参考答案：护土固根。确保重点，兼顾一般。
Where have you been all these days? We are very _____ about your safety. [ ]
A. interested
B. frightened
C. surprised
D. concerned
下列给药途径中，元首关消除的有______
A．舌下给药
B．直肠给药
C．喷雾给药
D．口服给药
E．静脉给药
