心材的疏导能力强,边材的利用价值高。
A. 对
B. 错
单子叶植物根和双子叶植物根的主要区别是维管束中没有导管。
A. 对
B. 错
If you agree to_____, please e-mail us by return and we will approach you further.
A. propose
B. proposing
C. be proposed
D. our proposal
The faster the shipping, the the price.
A. lower
B. higher
C. common
D. quicker