1、This tree is as tall as 30 mttres.改同义句? This tree is

1、This tree is as tall as 30 mttres.改同义句? This tree is _____ ______ 30 metres tall.
2、I couldn't carry that heavy bag.
I wasn't _____ ______ carry that heavy bag.
3、till和until的区别是什么?请详解.
4、用weigh描述体重,有几种结构?
5、very修饰什么词?
6、元音开头却用a的,常见的有几个?辅音开头用an的有那几个?
请逐条回答,不求速度,求质量

保证准确率!

= This tree is 30 meters (in height).
able to
没有什么区别,只有少数固定搭配中不能换用,如只能说not...until,不能说not...till
sb/sth weigh/weighs + 基数词 + 重量单位
sb/sth is + 基数词 + 重量单位 + in weight
sb/sth is + 基数词 + 重量单位 + heavy
sb/sth is as heavy as + 基数词 + 重量单位
very一般修饰形容词或副词的原级,意思是“非常,很”；
偶尔也可修饰名词,比如the very person,此时其意思是“就是,恰恰”.
a one-way street/raod/ticket（即a放在one前面）
a useful book...
a university
an hour,an honest boy...,an honourable teacher...