---Is she your mum, Helen?---________________.
Nanjing isn’t so large____ Shanghai. But it's the second____ city in East China.
---Which month has _______ days in a year?---February.
What_______ honest boy! And he is_______ best student of all.
We were swimming in the lake _______ suddenly the storm started.
The price of petrol(汽油) is not _______ that of last year, so some more people are planning to buy cars.