以下所列林种类型中,不以防治水土流失为主要目的的类型包括()。
A.坡面防护林
B.经济林
C.用材林
D.薪炭林
E.防风固沙林
参考答案:B, C, D
(2013·安徽蚌埠一次质检)So quickly ________ is a possibility today may be a reality tomorrow.
A.are science and technology advancing that
B.science and technology advancing are that
C.science and technology are advancing what that
D.are science and technology advancing that what
哮喘持续状态是指严重哮喘持续时间达
A.24小时
B.10小时
C.12小时
D.16小时
E.6小时