______Ｉcould express my thanks to the traveler , he had already disappeared in the rain .
| A．Before | B．When | C．Until | D．While |
My parents always _______ great importance to my getting a good education．
| A．have | B．attach | C．accept | D．pay |
You can use a large plastic bottle, _____ cut off, as a pot to grow young plants in．
| A．the top is | B．the top of which |
| C．whose top | D．with its top |
Although at present human egg cells and embryos needed for cloning research are difficult _____, Newspapers _________ evil leaders hoping to clone themselves．
| A．to obtain; wrote | B．to obtaining; wrote to |
| C．to obtain; wrote of | D．to be obtained; wrote |
Quzhou is ______ most comfortable city, where you can visit a great many interesting places, such as______ mysterious Longyou Grottoes．
| A．a; the | B．a; 不填 | C．the; a | D．不填; the |
I have already forgotten ______ you bought the computer.
| A．that it was when | B．that it was what |
| C．what it was that | D．when it was that |