下列曲线正确的是[ ]
A．向稀硝酸中加水
B．双氧水分解
C．向等体积、等浓度的稀盐酸中加金属
D．向稀硫酸中滴BaCl2
答案：C
Jane was disappointed that most of the guests_______when she _____at the party.
A．left; had arrived
B．left; arrived
C．had left; had arrived
D．had left; arrived
面部的发育始于（）
A.胚胎第2周
B.胚胎第3周
C.胚胎第4周
D.胚胎第5周
E.胚胎第6周
