What is used to determine when the communications channels are clear and when a device is free to transmit data

As with any small island country, cuba has fewer natural resources than countries such as brazil. this affects their economy in that cuba a) exports only manufactured products. b) exports more products than it imports.. c) must import more products than it exports. d) has imposed trade barriers against the united states.

How can smart devices benefit businesses, organizations, and social communities in the global marketplace?

What is the output of the following program? #include using namespace std; class bclass { public: void print() const; bclass(int a = 0, int b = 0); //postcondition: x = a; y = b; private: int x; int y; }; class dclass: public bclass { public: void print() const; dclass(int a = 0, int b = 0, int c = 0); //postcondition: x = a; y = b; z = c; private: int z; }; int main() { bclass bobject(2, 3); dclass dobject(3, 5, 8); bobject.print(); cout < < endl; dobject.print(); cout < < endl; return 0 ; } void bclass: : print() const { cout < < x < < " " < < y < < endl; } bclass: : bclass(int a, int b) { x = a; y = b; } void dclass: : print() const { bclass: print(); cout < < " " < < z < < endl; } dclass: : dclass(int a, int b, int c) : bclass(a, b) { z = c; }