搁浅船舶需固定船体的情况是:()
Ⅰ、短时间内不能安全脱浅Ⅱ、防止因风浪影响而打横或墩底Ⅲ、防止向岸边更浅处漂移
A.Ⅰ
B.Ⅰ、Ⅱ
C.Ⅰ、Ⅲ
D.Ⅰ、Ⅱ、Ⅲ
参考答案:D
-How often do you phone your family?
-_____. [ ]
A. sometime
B. sometimes
C. some time
D. some times
下列实验装置所制取的气体中,密度一定比空气小,且易溶于水的是
A.
B.
C.
D.