Will you see to ______ that the luggage is brought back?
A.me
B.them
C.it
D.yourself
答案:C
木材的自由水处于()和()。
溴百里香草酚蓝指示剂的变色范围在非水溶液中的pH值为(),其颜色是由黄色变成蓝绿色
A.4.0到5.6
B.8.6到9.6
C.3.1到3.4
D.8.0到10