submerged rock, not dangerous to navigation
sunken wreck, not dangerous to navigation
towed-under buoy
All of the above
第1题：
A. upstream EBGP neighbors
B. downstream EBGP neighbors
C. upstream IBGP neighbors learned by IBGP peers
D. downstream IBGP neighbors learned by IBGP peers
第2题：
How should you signal the crane operator to lower the boom and raise the load ________．
A.Extend arm and point finger in the direction to move the boom
B.Extend arm with thumb pointing downward and flex fingers in and out
C.With forearm vertical and forefinger pointing up，move hand in small horizontal circles
D.With arm extended downwards and forefinger pointing down，move hand in small horizontal circles
第3题：
Restricted areas at locks and dams are indicated by ______.
A.flashing red lights upstream and fixed red lights downstrem
B.yellow unlighted buoys
C.signs and / or flashing red lights
D.red daymarks upstream and green daymarks downstream
第4题：
波纹/波痕（ripple）
第5题：
How should you signal the crane operator to lower the boom?______.
A.With arm extended and fingers closed, point thumb downward
B.With arm extended downwards and forefinger pointing down, move hand in small horizontal circles
C.Extend arm with the palm down, and hold this position rigidly
D.With hands clasped in front of your body
第6题：
How should you signal the crane operator to hoist ________．
A.With forearm vertical and forefinger pointing up，move hand in small horizontal circles
B.With arm extended downwards and forefinger pointing down，move hand in small horizontal circles
C.Extend arm with fingers closed and thumb pointing upward
D.Place both fists in front of body with the thumbs pointing upward
第7题：
A V-shaped ripple with the point of the V pointing upstream in a river may indicate a _____.
A.submerged rock, not dangerous to navigation
B.broken wreck, not dangerous to navigation
C.towed-under buoy
D.All of the above
第8题：
有如下程序：#include ＜iostream＞using namespace std;class point{ int x, y;public: point( int vx, int vy ) { X=vx; y=vy; } point() { x=0; y=0; } point operator+ ( point p1 ) { point p; int px = x + p1.x; int py = y+ p1.y; return point( px, py ); } point operator-( point p1 { point p; int px = x - p1.x; int py = y - p1.y; return point( px, py ); } void print() { cout＜＜x＜＜","＜＜y＜＜end1; }};int main(){ point p1( 10, 10 ), p2( 20, 20 ); p1 = p1 + p2; p1.print(); return ();}执行后的输出结果是( )。
A．10, 10
B．20, 20
C．10, 20
D．30, 30
第9题：
How should you signal the crane operator to raise the boom?_________.
A.Extend arm with the thumb pointing up and flex the fingers in and out
B.Place both fists in front of the body with the thumbs pointing upward
C.With forearm vertical and forefinger pointing up，move hand in small horizontal circles
D.Extend arm with fingers closed and point thumb upward
第10题：
在Curver Editor中，可以添加动画声音的选项应为（）。