We know that you are leading exporters of coal and you can provide the quantity we need.
我们知道贵方是主要煤炭出口商,能满足我们的需求量。
It is better to ask for help at the beginning rather than to wait until a busy period when everyone is rushed off their feet.
最好在开始工作时就请人帮忙,而不是等到大学都忙得不可开交的时候。