Six months later John had developed literacy and numeracy skills, plus confidence.6个月后，约翰已经渐渐能够识字和算数，也有了自信。standards of literacy and numeracy读写和计算的水平There was also a strong link between children'slow maths scores an...
催化剂是一种能加速化学反应的物质.A catalyst is a substance which speeds up a chemical reaction.各种陶土管用作转化催化剂的载体.Various ceramic materials have been suggested as supports for reforming catalyst.经过泡水试验,催化剂应不开裂或破碎.To pass the water test the...