Answer:
At an angle of 
Explanation:
Assume the river flows from East to West so for the swimmer to cross across it, assume he crosses it from West to East.
The resultant speed will be given by

The temperature of 20°C is equal to 68.0<span>°F</span>
Answer rain gauge measures rain shadow units millimetres
Answer:
Batteries are systems that store chemical energy and then release it as electrical energy when they are connected to a circuit. Batteries can be made from many materials, but they all share three main components: a metal anode, a metal cathode and an electrolyte between them. The electrolyte is an ionic solution that allows charge to flow through the system. When a load, such as a light bulb, is connected, an oxidation-reduction reaction occurs that releases electrons from the anode while the cathode gains electrons
Explanation:
Batteries always use direct current. That eliminates A and C. The other part of the answers is just asking what direct/alternating means. Alternating currents change directions moving one way then another. Direct current only moves in one direction. Therefore, the answer is D, since the current is direct and direct currents move in one direction.