方程4x+2x-2=0的解是______．
令t=2x，则t＞0，
∴t2+t-2=0，解得t=1或t=-2（舍）
即2x=1；
即x=0；
故答案为0．
Catherine's mother doesn't _____ of her meeting her online friends in case she meets with some bad guys. [ ]
A. allow
B. permit
C. forbid
D. approve
水锤也叫水击。
