"挖空"现象
参考答案:
"挖空"现象:脉络膜黑色素瘤患者超声显示内部回声前部光点密集,后半部衰减即所谓"挖空"现象,可有声影。
----- does your brother watch TV?
-----Every Saturday and Sunday.
A.How many
B.How often
C.How much
D.How long
This lifeboat is for women and children only. You _____ wait. [ ]
A. should
B. need
C. can
D. would