They've promised to keep both we quality and the quantity of the 300 bicycles in conformity with the contract stipulations.
他们已承诺那300辆自行车的质量和数量一定与合同规定相吻合。
It is because in the modern world, English is very widely used for business between different countries.
这是因为在现今世界,英语广泛应用于国与国之间的贸易往来。